All language subtitles for C-Programming-Tutorial-for-Beginners_en

I'm gonna be teaching you guys everything you need to know to get

C is an awesome programming language and it's actually one of the

A lot of modern programming languages are based off of C

so it's a really good idea if you want to get into C or even if

C++ to learn the basics and in this course, we're gonna cover

I'm gonna talk to you guys about installing a text editor and

I'll talk to you guys about you know, what is a program and how

Read the instructions that you give it and we're gonna get into

We're gonna look at things like if statements and loops we're

We're gonna talk about the different types of data that you can

We're gonna talk about things like structures and the functions.

And basically I'm just gonna give you a full overview of all of

So by the end of this course, you'll have a really good

Which you can build on you can kind of go forward and learn some

I'm really excited to be bringing you guys this basic course on C

I'm really excited if you guys to dive in and start using these

So feel free to click around through all the videos and hopefully

I'm gonna talk to you guys about getting everything set up to

We're actually going to need two things

The first thing we're gonna need is an environment where we can

Now there's a bunch of these different environments. Essentially.

so anything that can you know, allow you to

Write text and then save that text in a specific file format is

although when we're working with C a lot of times it can be useful

Development environment. Basically, this is a special text editor

And so I'm gonna show you guys how to install an IDE called code

We need to write our C programs is going to be something called a

It means we can basically write out

You know instructions that we want to give to the computer but

Compiled which basically means like translated or transformed into

So we're gonna basically download and install a special program

I am going to come over to my web browser and

I'm just gonna go up to the Google search bar. And I'm gonna

Code blocks C. And this link should come up. It's code blocks org

This is an integrated development environment

It's basically a text editor that will make it really easy for us

There's a bunch of options here one says download the binary or at

We want to click on download the binary release. This is going to

So if you're on Windows or Linux or Mac, you can install it from

So depending on the operating system that you're on you want to

So I'm gonna come down here to the windows option. You'll see

So there's a bunch of options here. What we wanted download is

And then the version number and then it says min

Basically what this is is it's gonna allow us to install code

So we're gonna be able to install that IDE program, and we're also

Compiler. So remember I said we needed those two programs

We needed those two things and this is actually going to give us

So I'm gonna come over here and click on the link to download this

And you can see it's gone ahead and downloaded that

So now let's head over to our downloads folder and I'm just gonna

so this should open up a window where we can set up the program

Let's just click through this

I'm gonna agree the license and basically just leave all the

alright when that's done installing it's gonna ask us to run code

It's giving me this little window here. It says compilers auto

So you can just click on the one up here. That's highlighted

It says GNU GCC compiler and I'm just gonna click set as default

We now have code blocks installed

We're gonna be learning about setting up code blocks writing our

But for now, you have everything you need to get started

In this tutorial I'm gonna talk to you guys about getting

Then this video will basically show you how to get everything set

We're actually going to need two things. The first thing we're

We're going to use the text editor to write our C programs in and

C programs but there's actually a special type of text editor

Integrated development environment and it's basically a special

Write and run and manage our C programs

So that's the first thing the second thing we're gonna need is

So essentially what we're doing when we're using it is we're

We're writing instructions that us humans can understand and work

Translated or transformed into a language that the computer can

It's gonna take our C programs and essentially just translate them

So the first thing I'm gonna do is show you guys how to install

So what you want to do on your Mac is go over to the search bar

Click enter and a window that looks like this should pop up now

The terminal is basically a program that allows us to interact

So we're actually gonna need to use the terminal in order to do

so the first thing we want to do is check to see if you might

You might already have one. So you just want to type in C C

You'll see over here. I have AC compiler installed. So I'm getting

It says like si Lang and it's giving me you know, a bunch of

If you have that, then you have your C compiler installed and

But if you don't have that I'm going to show you guys how to get

So all you want to do is just type in

select and then the space - - install and

Click enter and you'll see I'm getting an error here because I

But if you don't already have them installed and obviously then

Then this is gonna go off and install everything. You need to get

so once you run that Xcode select command just type in CC - V

You should be getting this version number

Alright, so now that we have our C compiler installed

What we want to do is download an IDE

So we want to download a special text editor that we can use to

To my web browser and I'm up here at a website called code blocks

It's one of the most popular free

IDE s for programming and C. So we're just gonna come down here to

There should be a few options here download the binary released

We have a bunch of options for windows linux and mac click the mac

You'll see that here is what we need to install code blocks on the

So if you go over to the right side here, there's a link to

So I just clicked that link and it should start downloading

Automatically when that finishes downloading, let's head over to

so I'm just gonna double click on this and

They should give us code blocks now

All you want to do is just drag and drop code blocks into your

So you have code blocks installed and ready to start following

In this tutorial, I'm gonna talk to you guys about getting our

So we're gonna load up a C file and we're gonna be able to get

so I'm gonna open up my codeblocks program and this is the

IDE that I'm gonna be using for the rest of this course

So I'm just gonna double click on it and it should start opening

There's a bunch of different options like create a new project

So we're actually going to want to create a new project

So whenever we're gonna start writing some C files

We're gonna want to create a new project in code blocks

so you can either click this button right here, or you can go up

projects so either way it's gonna bring you to this window over

There's gonna be a bunch of options here

Just these are different types of like C projects that we could

This is like there's a basic C project that you can run on your

So click on console application and then click go and I'm just

C++ or C now C and C++ are both

Different programming languages for this course, we're gonna be

So just highlight C and click Next and we're gonna give this a

I'm just gonna call mine draft and we're gonna have to put this

Inside of a folder so I'm gonna open this up and I'm just gonna

Click Next and you can leave all of these options as the default

our first C project in code blocks now over here inside this

Draf is right here. So that was the name of the project that I

So I'm going to click down and you'll see we have this file here

And this is a file that got automatically created for us by code

I'm just gonna right click and open it and you'll see over here.

There's these little lines of code that say include down here.

Program that we're given by default when we created our C project

Right, essentially what this program does is it prints out hello

So in order to run this program and test it just to make sure that

I'm gonna come up here and you'll see that there's this

Green play button over here and it just says run when I hover over

This file that we have open right here main see is gonna get run

So we're essentially telling code blocks to run this file and

So when I click the Run button, we're getting this message. It

do you want to build it like yes, and

Now over here this little window pops up

Basically, this is the command prompt. So whenever I run a C

So if I was to exit out of this and run this program again

You'll see this window pops up again. And it basically just

All we're doing is we're printing out

Hello world onto the screen and that's actually what this

Executing the program and it's printing out whatever we told it to

So it's printing out hello world over here and printing something

And that's one instruction that we can give to the computer

But as we go through this course

we're going to learn all sorts of instructions that we can use but

C project set up and to test our main dot C file

So as long as everything works here and you're good to go and now

In this tutorial I'm going to talk to you guys about the basics of

So if you've been following along with the course up to this

We've installed a C compiler and we set up our first C program.

Inside of code blocks. So now essentially what we have is this

I just kind of want to point out a couple things that are in here

We have these little instructions which are just called include

Later on in the course. We're gonna talk about what these are

How they're helping our program, but for now just know that in

We're gonna need to have these guys up there

next thing we have is this little block of code called main and

It just has this name main you can see there's an open and closed

And this is actually what's called a method and don't worry too

we're gonna talk more about those in future, but essentially a

container where we can put some of our code and

This method main is very important because this is the method

when we run our program so in C we can actually write out a bunch

instructions for the computer and then we can run our program so

Execute those programs and whenever the computer executes our C

It's gonna look inside of this main

method in other words that's gonna look inside of all the code

Execute that code so I have this instruction here

It's called printf and basically this is just printing out some

It's gonna come into this main method and it's gonna execute all

So if I was to run my program then this is gonna work now

Let's talk about actually running a program whenever we want to

We actually have to do two things

The first thing we have to do is what's called building a program

And basically what that does is it takes all of this C code

It translates it into a language that the computer is going to be

So it's essentially taking this C program code

Translating it into computer code and then the computer can

So the first thing we have to do is always build our C file

The second thing we have to do is run the file that gets built

so once we've built this program

we've compiled it down into code the computer can understand we

execute that code and in code blocks

It's actually really easy to do this. So

we can come over here and this little gear icon will allow us to

then this play button will allow us to run our program but a lot

Programming you're gonna want to build and run your code at the

you're just gonna want to build it and run it just to see what

So we have this option over here called build and run and this

So generally as you're going through this course you're gonna want

That's build and run options when I click this

it'll essentially build my program run it and then it'll show up

Console window you can call it. So a lot of people would refer to

Information that we tell it to so if we write a C program that

Then we wouldn't actually see this but since we're using this

So let's talk about how these programs actually get executed

We have a set of instructions

So when I'm writing a C program, I'm basically writing out a set

Right a recipe is essentially just a set of instructions that when

You know cooking or baking something delicious, right? And that's

It's a set of instructions that when executed correctly

will result in the computer doing something for us and one of the

computers is that we can program them to do anything and

C is one of the best languages to do that with so let's look at

It's called print F and this prints something out onto the screen.

Semicolon and this semicolon is actually really important

So whenever we write an instruction in C

We always want to end it off with a semicolon

That tells C that we're done with that instruction and we want to

instruction and I could paste it down here and

Now we're basically going to be executing this instruction twice

so if I was to run and build my program you'll see that we're not

So when we run our program the program comes down into this main

So it starts with this first instruction. It executes it, right?

So it prints out hello world onto the screen and then it also

So this backslash n is like a newline character and that'll move

When it's done with this instruction, it moves on to the next

So as we go forward and we learn how to write in C

We're gonna learn more and more complex instructions

And we'll be able to use all those instructions in conjunction

This is really the only instruction that we know which is printf

Instruction in order to draw out a little shape onto the screen

So I'm going to show you guys how we can draw out like a little

I'm gonna take this printf and I'm actually just gonna get rid of

so I'm just gonna copy it and we'll paste it down here, maybe four

What I can do is I can specify

Instructions to the computer that will tell it to draw out a

So down here I could make like a forward slash and over here

We'll make another one and I'll make another one and I'll make

I've drawn like a little diagonal line with these forward slashes.

I'm gonna put one here. I'll put one here and

finally, why don't we draw some underscores and then we'll put one

Backslash ends are just printing out a new line. So anytime I

So it'll print this guy out now on the line down the line below

So if I was to save my program and execute it now the computer is

Of these instructions in order and we'll be able to print out the

You see over here. We get our shape and

One thing I really want to stress. Is that order matters?

So if I took this instruction and I placed it up here as the first

This is gonna get printed out first

So when I run my program you'll see that we're printing out this

Funky looking shape and that's because we changed up the order of

So the computer changed the order in which it executed those

Semicolon after each line of code. So that's kind of the basics of

That's essentially all you need to know when we're writing a

we're specifying a list of instructions that we want the computer

Depending on which instructions we give the computer and which

That'll determine what the program does and as we go through this

we're also going to learn how we can take simple instructions like

Do different things with them to make our programs a lot more

In this tutorial I want to talk to you guys about variables in C

Now when we're using C programming language a lot of times we're

so there's gonna be different data values or different information

Sometimes it can be difficult to maintain and keep track of all

Essentially a container where we can store different pieces of

we could sort of things like numbers or texts or characters and

These variables make it a lot easier for us to keep track of and

So I'm gonna show you guys basically how variables can be useful

But down here. I have a very basic program. I'm basically just

Printing out a little story. It says there once was a man named

He was 70 years old. He really liked the name George but did not

We're just printing out a bunch of different lines of text

and then when I run this program

You'll see we print out the actual story so over here we have our

But let's say that I'm reading through my story. I'm reading

I think I want to change the character's name

So instead of calling the character George, why don't we call him

I'm gonna have to look through my entire program and find every

So right here is one change it to John remember keep looking and

So I had to manually go through and change every instance of the

To John and let's say that okay. That sounds pretty good

But maybe I'm thinking I want to make the character a little bit

I'm gonna have to look through my entire program find every place

So there and there there you go

I changed the program I updated and modified it now

If I was to run this program then all that information will be

I'm dealing with a very short story. I mean, this is four lines

We only mentioned the character's age and name twice

But imagine if I was writing out a huge C program that had

So story had hundreds of lines and maybe we mentioned the

Well if I wanted to change the characters age your name?

I would have to go through and manually change it in every single

Basically, that's not a good way for us to manage and maintain the

All right. We basically have two pieces of data that we're working

Consistently in this program the characters age and the

What I want to show you guys now is how we can use variables to

So remember a variable is basically just a container where we can

so I want to create two variables which will store the character's

The character's age and I'll show you guys how this can make our

Manage up here above these print statements

I'm just going to make a new line and I'm gonna come over here and

Now whenever we create a variable in C, we have to give C a couple

So we have to basically tell C a couple different things

The first thing we have to tell C is what type of information we

I'm gonna get into the different data types that we can represent

but for now just know that there's a bunch of different types of

Numbers characters we can store text we can store decimal numbers

I'm going to store the character's name and the character's name

So in order to create this variable

The first thing I have to do is tell C that I want to create a

So to do that, I'm just gonna type out char just like that and

Hey, we're gonna store characters inside of this variable

I want to type out the name of the variable that I want to create

Remember of variables that contain and it's a good idea to give

Descriptive names and those names will basically let us know what

Character name and now what I want to do is I basically want to

I'm telling to see that I want to store a character

But in C we can also store instead of just storing like one single

we can store a bunch of characters and that would be kind of like

you know a name so there's like four characters in here in order

Type the character Abel's name

We're gonna have to make an open and closed square bracket

And that's gonna tell C that we want to store a bunch of

So I'm gonna type char a character name open a close square

So I'm essentially assigning a value to this variable and I'm just

We're gonna type out the value that we want to store

So in my case, I'm just gonna store the character's name, which is

We're gonna have to end this off with a semicolon

so essentially what I did here was I

Created a variable and I told C what I wanted to store in the

I wanted to store a character. I gave this variable a name. It was

I used these open and close square brackets to sell C that I

Now what we can do is we can make another variable to store the

So in this case, we're gonna want to do something similar, but

There's a bunch of different ways that we can store numbers and

so we're gonna use something called an integer and an integer is

That basically stands for integer. And now we're gonna give this a

Character age and I'm gonna set this equal to a number

So in our story the character is 35

So I'm just gonna type out 35 and now we can again end this off

So I have two variables here. This one's storing a collection of

Now the question becomes how can we use the inside of our

What we can do is we can print them out alongside of this text and

Instruction in order to do that so I'm gonna show you guys how to

So basically, I'm gonna go over here where we have the character's

I'm gonna erase this and I'm gonna replace it with a % and an S

I'm just gonna type in the variable name. So I'm gonna type in

character name and basically what's happening is when we use this

We're telling see that inside of this string of text here

We're gonna want to insert a another

String and a string is basically just a collection of characters

So when I say % s this is basically a placeholder and I'm telling

I'm gonna insert a string into here and

Over here I use this comma and then I type out the string that I

It's character name and so basically over here

It's gonna say there once was a man named

% s and it's gonna replace % s with whatever we specify over here

So it's gonna replace % s with the value that's stored inside that

so I'm gonna save this and we'll run our program and

Now you'll see that it's still printing out there once was a man

Even though we didn't actually type out John over here

We just typed % ass in the character name so I can do this in this

We're also using the character's name so I can type % s and over

Character name and again. This is going to act as a placeholder

For this string of characters that we specify over here

Let's do the same thing with the age so over here we have the age

I'm going to do something similar and I'm gonna say percent

but now because I have a number instead of using percent s I'm

Percent D and that basically means that we're gonna insert an

So I'm saying he was percent D years old and over here. I'm gonna

, and I'm just gonna type out the name of the variable that I want

Character age and we're going to do this one more time down here.

Character age so essentially what I'm doing is I'm printing out

That's inside of character age where I specify this

Let's go ahead and run our program and now you'll see it's gonna

the same name and the same age

Except I didn't have to actually type out the character's age and

I just referred to the variable and what's cool about?

Variables is I could come up here and let's say I wanted to modify

all I would have to do is modify it in this one spot so we could

We could also change their age to like 67

And now when I run my program all of that's gonna get updated in

so now it's using the name Tom and the age of

67 in our case. We only mention the character's name and the

But you can imagine if I was mentioning this variable like ten or

Having to change it in each one of those individual spots would be

So variables are great because we can store the value one time and

We just modify it in one place. So another cool thing that we can

So let's say that halfway through the story. I wanted to change

I can make a new line and right above these print statements. I

character age and I can just set it equal to something else so we

Again, we want to include that semicolon. So now halfway through

So you'll see it says there once was a man named Tom, he was 67

The age is being a 30 so we actually modified the value that was

Halfway through printing out our story and that's really why

So that's kind of a basic overview and introduction into what

And over here again, we're storing a collection of characters,

But there's some other data types that we can also represent

So in addition to representing like a string or a number we can do

And I'm going to talk about that in the next video

But for now, this has just been a basic overview and introduction

In this tutorial I want to talk to you guys about data types in C

We're gonna be dealing with a lot of data

So generally when you're writing programs, you're gonna be dealing

I just want to talk to you guys about what types of information we

Inside of our C program and these are called data types. All

So what are the different types of data that we can work with in

So I'm gonna show you guys all those different data types right

So a lot of times in C when we're working with data, we're gonna

so I'm just gonna show you guys a bunch of different variables

Can store inside of those variables?

so remember whenever we create a variable and C we have to tell C

information and the first piece of information we need to tell C

Data that we want to store inside of that container inside of that

so let's talk about the different types of

One of the most basic types of data and probably one of the types

Gonna be numbers. There's actually two very important types of

So the first type is called an integer and an integer is basically

so it's a counting number right if I was counting on my fingers 1

I'm just counting out whole numbers and I'm not saying like 1 1

2.3 like I'm counting in whole numbers and that's what an integer

So to create an integer we could just say int

And we'll give this a name so we could say like age and we could

Now whenever we want to use an integer in C. We always just want

So you'll notice I'm not putting quotation marks or parentheses or

I'm just typing out the number like that. And now we actually have

another type of number we can create is a

Decimal number so this would be a number unlike an integer

So it would be like 2.5 or eight point six seven or seven point

It's a number that has a decimal point associated to it. So

there's something called a double and there's something called a

Float, and I'm not gonna get too much into the difference between

But as a beginner to see for the most part

You're just gonna want to use a double

So I'm just gonna type out double and this could be like someone's

3.7 or whatever so, you know, you can use the double to represent

it's also important to note that I could also represent like the

3.0 and that's gonna be a decimal or I could say 40 point O

So the difference between 40 and 40 point O is that forty point O

It's a decimal number and 40 without the decimal point is an

So that's something just to keep in mind so you can make this like

So those are the two basic types of numbers integers and doubles

Now the next type of data that we're gonna want to store or is

single characters inside of a variable so I could just say

CH AR and that stands for character and we could give this a

So maybe it'd be like someone's grade and when we create a

We're basically going to specify the character that we want to

So inside of these single quotation marks, I could put a letter I

C d AF basically you can put any character that you want to store

So if I put an A here now, this character variable grade is gonna

It's important to note that you can only store one character so I

And that's actually gonna throw an error

All we can do is store one single character, but these three are

So these are the basic types of information that we can deal with

Three data types, we can represent all sorts of information

I also want to talk to you guys about one sort of extra data type

Technically a data type in C. It's technically like a modification

So you'll notice when we create a character we can only store one

But a lot of times we're gonna want to represent more than one

Character so we're gonna want to represent like a string of

so it's a collection of characters that are grouped together and

String so I can basically say char

I can type out the name of the string that I want to create so I

can make an open and closed square brackets and this is basically

string a bunch of characters together and

What we're actually doing is creating something called an array

But just for now know that we can create a string of characters by

Specifying the name these open and close square brackets, and then

So instead of these single quotes up here

We're just gonna use double quotes and I could type in like a

String of text I want here and this will get stored inside of

Variable which like I said is technically called an array now

Doing something like this or creating this like string of

So like these variables up here we could modify them

We can give them new values but you can't do stuff like that with

So just know that this is like a special type of data and it's

But that's one of the basics of working with data and those are

In this tutorial I want to talk to you guys some more about the

so if you've been following along with this tutorial

We've been using an instruction and our C programs called

Printf and printf basically allows us to print different things

We're going to talk more about what printf does and we're gonna

And also things like different data like numbers and strings and

So in order to use printf we just type out PR int F and we're

Now printf is what's called a function and basically what that

in our case printf just print something out onto the screen write

Printing something out and it basically works how you'd expect it

specific piece of information and generally when we're using

Text so I can make an open and closed quotation marks and I could

And now this will print out onto the screen. Hello and

Inside of printf I can use all sorts of special characters

so if I wanted to create a new line, for example, I can make a

Down here. I could type world and now this will print out a new

So you'll see hello world on different lines

We can also use these special characters

So for example, I could print out like a quotation mark

So if I just printed a normal quotation mark right here, you'll

counting this as the entire string if I wanted to change that I

Quotation marks when I run my program you can see we have a

you can specify some text that you want to print out onto the

Extremely powerful and we can use it to print out different pieces

So in addition to just printing out plain text inside of these

I could also print out other types of information. For example, I

And if I wanted to print out a number I would have to use

Basically tells this printf function that we want to print out a

That's not just plain text like this

So if I said % and then I said D

This would actually allow me to print out a number

So generally when we use these format specifiers uses % and that

Special and then after that we would type in a specific letter and

so if I said % D this means that we want to print out an integer,

All I have to do now is I can make a comma and over here

I can specify the integer that I want to print out so I could say

500 to the screen so you can see over here

we're getting 500 and this is cool because we can interweave these

% D and this acts as a placeholder for this number over here

so when I run my program now it says my favorite number is

500 and that's really cool. We can also use multiple format

so in addition to just using this percent d I can also specify

You'll notice that this is structured similarly to percent d % s

So I can include some more text just like this

so if I said % s I can make another comma here and I could say

Number and now this is gonna print out my favorite percent s so

It's gonna insert that in and it's gonna say 500. So now when we

it'll say my favorite number is

500 and you'll notice here that I'm using multiple commas. So I'm

I have a comma and I'm specifying this string that I want to print

integer, and so basically the order that you put these format

String of text is the order that you need to include them using

So you're going to separate each of them using a comma hoon

We can also use a bunch of other ones

And I'm going to talk to you guys about some of the most common %

but if we wanted to print out a decimal number

for example a double we could say percent F and this is gonna

Decimal number so I could say like 500 point nine eight seven five

And now this is gonna print this out on to the screen. Actually. I

So my favorite number is five hundred point nine eight seven five

So essentially you can use these print FS and you can use these

So like this is just some general text output and we can use these

Like numbers or you know other strings and stuff like that and

So if I was to create like a number variable up here, I can call

I can use this variable and print it out inside of this printf so

Instead of printing out this number we can just access that

And this will allow me to print out that variable using that

90 so that's the basics of using printf

This is a very awesome tool that we can use and printf is

So when we're running our programs a lot of times we're gonna want

About what's going on about what they're doing in printf can allow

So don't be afraid to use these different access modifiers. Like I

Those are all sort of the common ones and you can also use % C and

Character so I can come over here create like a character

We'll call it my char and just set it equal to like lower case

I and I could print this out using % C. So now we could say my

Play around with printf. It's extremely useful and it's really

I want to talk to you guys about working with numbers and see now

We're gonna want to do different things with numbers whether

Subtracting doing math with numbers or you know, really just

So I'm just gonna give you guys a basic overview of a lot of the

We're also gonna talk about how different number types in Iraq. So

So down here I am printing out a number so you can see I'm using

And % f stands for like a floating-point number so that could be

so we put % F in here that's gonna allow us to print out a decimal

You can see I can run my program and it'll print out 8.9 and

But it's also printing it out to a very precise

decimal point and that's what C is always gonna do so it's always

A very precise decimal. So using these decimals I can do all sorts

So obviously I can just print out the decimal but I could also do

This is gonna go ahead and be able to do that for us when I run my

Not only is it gonna like print this out but it's gonna do the

so in addition to addition we can also use subtraction division,

Multiplication which is going to be in asterisks and you can use

Operations addition subtraction multiplication and division. So

floating-point numbers so like doubles and floats

Alongside integers. So let's say I was going to add an integer

With a double. So if I said 5 plus

4.5. Well, actually when we do this this entire answer is going to

Decimal number so when I say 5 which is an integer plus 4.5. We're

and basically any operation that you do between an integer and a

So that's important to realize but if I was to change this to four

This isn't gonna work anymore because this is asking for a

So when I do math with two integers

it's going to give us an integer back and if I do math with a

Floating-point number back. It's also important to realize for

This should actually be a decimal number right and you'd expect us

But if I just print it out percent D. So I printed out the result

I'm actually gonna get an integer back

So when I run the program you'll see we're getting a one here, but

But it's one with a bunch of decimal points after it. Right? It's

But when we just do math with two integers

we're gonna get an integer back if I was to say five divided by

Decimal now, we're gonna get the entire answer back. So we're

So that's just a little bit about dealing with integers and

We could also take these and put these into variables

so, you know in addition to just having numbers down here I could

You know num set it equal to six and we can go ahead and print num

So now I will be able to print out that variable with no problem

So it can be really useful sometimes to store these numbers inside

I also want to talk to you guys about using more complex

mathematical functions now in C

Functions which are basically just little blocks of code that we

Certain things for us. So they're like modify a value or give us

I'm gonna show you guys a couple functions that we can use with

So I'm just going to come over here and I can actually start using

Out the name the function that you want to use

So by default C is going to give us access to a bunch of math

So we really don't have to do anything

all we have to do is just type in their names and I'm gonna show

Oh w then I'm gonna type an open and closed parenthesis and inside

I can actually give this two numbers

what this is gonna do is it's gonna take the first number that we

second number so if I said like 2 & 3

And you'll notice I'm separating them with a comma this is

So to give us 2 cubed so when I run my program and actually we

So this is gonna give us a decimal number back. So I need to print

When I run my program we're gonna get 8 back just like that. So

Cubing 2 I could say like 4 raised to the third power and now we

So that can be pretty useful. There's a couple other ones. I'll

So this will allow you to take a number square root

So if I said like 36 in here now, we're gonna print out the square

Which is gonna be 6 and there's a couple other ones

So let's say that I had a decimal I could say C EIL which stands

So if I have like thirty six point seven or 36 point three five

This is gonna give us the hot the next highest number. So it'll

We can do another one which is called floor and floor. We'll do

We'll just round the number down no matter what. So if I have like

So there's all sorts of little, you know things we can do

little functions that we can call and get information about

Functions will either like modify a number so it would like give

Or sometimes they'll like give us information about numbers

So that's sort of the basics of working with numbers, you know

you can do all sorts of math with numbers you can add in some to

Multiply add subtract integer numbers and floating-point numbers.

different things with numbers and if you want to find some more of

All you have to do is just go online and Google search for C math

there's like dozens of these little functions that you can use,

I want to talk to you guys about using comments and see well

Which actually gets ignored when we run our program, so if you

you can use a special starting and ending tag and any of the

Text any of the code anything that you put inside of that tag

So we can use comments to do all sorts of things, you know

You can leave little notes or little comments inside of your

Temporarily disable certain lines of code. They can be really

So I'm gonna show you guys the basics down here in my program if I

Using a forward slash and an asterisk and you'll see when I put

and basically what this means is anything that comes after this

Order to close off the comment. I can use an another asterisk and

You'll see the code changed back to normal code

Inside of these two asterisks is I can basically write out

If I you know wrote out like my program and I ran my program this

So it's just gonna print out comments or fun

It's not gonna do anything else and you know

Like I said comments are really useful so I could leave a little

I could write something like to do like I have to do something and

Explain certain lines of code so I could put a comment here and I

So maybe you know, this was like a really complex line of code

We could use this text in order to explain it

You can also use comments to do something called commenting out a

So for example, let's say I wanted to run my program but I didn't

Well one thing I could do would just be to delete the entire line

Right so I could delete this code and now I can run my program and

It's no longer gonna do anything. But here's the problem in order

so instead of deleting it I could just bring it back and I could

surround it with these comment tags and

Now the computer is just gonna ignore it. So it's not gonna render

So now when I run my program it's gonna do the same thing. It

But I didn't have to actually delete the line. I could just

So a lot of times when you're writing programs

You might want to try to run your program without a certain line

you know series of lines of code and instead of deleting them and

See will basically ignore them so that can be really useful

So those are the two basic uses for comments and essentially

It's just a way that we can write out information in our files.

And so you can really use comments to do whatever you want

Now I will say one best practice with comments is to use them

Generally, you only want to use a comment when you absolutely have

File and there's like comments littered all around and obviously

I mean no one's stopping you but as a best practice going forward

I think generally only using comments when they're absolutely

But again, it's open, you know, you can use comments for whatever

In this tutorial I want to talk to you guys about constants in C

Well constant is a special type of variable and C which can't be

So when I create a constant and C, I'm basically creating a value

Unable to be modified. So I'm gonna show you guys basically how

Let's say I created an integer and I just called it num and I set

right, and then I printed out that integer onto the screen so we

We're just gonna pranaam right so I can create this num variable.

I wanted to modify num so I could basically say num is equal to 8

The value that's stored inside of the num variable

And let's come down here and we'll print this out as well. So

And we'll print out num again. And actually I'm gonna print out a

So when I go ahead and run this program and I forgot to send me :

you'll see we're printing out five and then we modified the value

But in certain circumstances and see you're gonna want to create

So these would be values that just like can't change and those are

So if I wanted to make a num a constant in other words, let's say

I didn't want the num variable to be able to be modified in my

I could come over here and I could say

Const so Co NS T and I'm gonna say that right before I declare the

Right after you declare the type, but I've always preferred to

So I say Const int num 5 and now this program is actually gonna

You'll see down here. It's getting highlighted in red. That's

So I'm trying to modify a num down here

But I can't because I gave it this Const keyword because it's now

So in a lot of cases you want have variables that just can't be

In a situation like that you want to make them consonants also a

We'll give them all uppercase names and this isn't required

this is just sort of like what a lot of developers will do so

Um like this they would say like num or maybe this is like your

So that would be how you could like distinguish two words

but generally like constants will be all capital and that's just

Unchangeable that they're constants. But again, you don't have to

so this is one way that we can create a

constant, and we basically create a constant variable that can't

Just like any number or any text that we're using in our program

So, for example, I'm gonna get rid of this if I came down here and

So let's say I just printed out like Hello. This is actually also

So this is just like a string of characters a string of text

That's also considered a constant because it's just like text on

so you would also consider this a

Constant if I was printing out a number to like let's say I came

77 T is also considered a constant

So it's just considered to be like a piece of information or a

That is sort of unchanging. Right? So 70 this isn't gonna change

I mean unless I physically came in here and changed it like

This value is always gonna be 90 no matter what I can't modify it

So that's also considered a constant

But I would say like for the most part like where this is going to

But creating constant variables variables that can't change

In this tutorial I'm gonna show you guys how to get input from a

So a lot of times in our C program

So we're going to be working with all different types of

Information from the user so I'm going to show you guys how we can

We can take that information store it inside of variables and then

So this is gonna be pretty cool. So down here

I will basically write out the code for this and the first thing

We want to prompt them. So I want to prompt the user, you know, as

So I'm just gonna say printf and over here. I'm just gonna print

Ask the user to enter in their age. So well, I'll show you guys

so I'm just gonna say enter your age and

Now that we've prompted them to enter their age I need to do two

So the first thing I want to do is create a variable where we can

the input that the user puts into the program

So I want to create a variable where we can store the age that the

So I'm gonna create an inn over here. Oh, it's called age. And I'm

so all I'm gonna do up here is just

Declare the variable. I'm just gonna tell see that I want to use

But I'm not gonna give it a value in other words. I'm gonna allow

So down here I want to be able to get input for from the user so I

scanf is basically going to allow the user to enter in some

This works similar to printf it's kind of doing the opposite of

Scanf is allowing the user to input something

Into the program and we're gonna make an open and close quotation

I basically want to tell see what type of information I'm asking

So in our case we're asking for an integer right age is going to

it's a whole number so I'm gonna accept as an input and integer

Over here. We want to tell C where we want to put integer

So I'm basically gonna tell see what variable I want to store this

I can essentially just type out the name of the variable here

But in order to get input from the user I'm actually gonna have to

So instead of just typing out age. I'm gonna have to type

And when I say ampersand age, this is what's called a pointer and

I'm gonna cover everything you need to know about pointers

But for now, that's a little bit beyond what we need to learn

so all you need to know is that when you're using scanf and you

An integer or a float or like a character you need to use this

So down here now that we've scanned for the users age. I'm just

So we'll just print out like you are and I'll say % D years old

I'm just gonna print out that age variable. So essentially what

I'm storing whatever age they enter inside of this age variable

So let's go ahead and run this program and we'll see how we did

So I'm gonna run the program and it says enter your age. So let's

It's can take that integer that we entered 50 store it inside of

You'll see over here. It says you are

50 years old. So that's how we can get an integer from the user

We can also get like a double from the user

so for example, I could say enter your GPA and so now instead of

asking for an integer we're gonna be asking for a double so I can

We could call this GPA and now I can do the same thing. But

I want to say L F and L F is basically going to tell this scanf

Double and then obviously instead of age. We're just gonna put GPA

your GPA is and then we can put % F because we're gonna be

I'll just say GPA. So you'll notice here in printf when we want to

We're using percent F to print it out. But when we're using scanf

So that's just like a little difference and now let's go ahead and

And we should be able to get a GPA. So let's say someone's GPA is

3.1. So that's how we can get a double. I also want to show you

so why don't we create a character up here and we'll just call it

Now when we want to get a character we can just say percent C and

I can just come down here and say ampersand grade and then down

Percent C and we'll go ahead and print out the grade

So now we should be able to get a character from the user

let's say I got an A and it says you're good as a so we can use

Input from the user we can store those specific types of input

I also want to show you guys one more thing we can do which is we

so in addition to getting numbers and a character, we could also

this is going to be a little bit different from

Doing like numbers and characters. So I want to kind of show you

Let's create a variable. We'll just call it. Let's just call it

Whenever we're creating a string of characters, we always need

I'm actually going to specify how many characters I want to be

In the past in this course when we when we've been creating

We've just kind of said like whatever. All right, we basically

But in this particular situation, we're not gonna be giving this

Like I don't know what the users name is gonna be like, I don't

They're gonna tell us what that is. And so if I'm not gonna give

I do actually need to tell see how big I want this variable to be

I need to tell see how many characters I want this variable to be

Allocate enough memory for this variable. So I'm just gonna put 20

And I think that's enough for a name so down here. We'll just say

I can use scanf in order to get input

in the form of a string but instead of saying percent see I'm just

Over here instead of saying ampersand grade

I'm just gonna type out the name of the string of characters. So I

Specify the name of the string so down here

it says printf your grade is and actually let's just say your name

I would have say percent s and then over here we can print out the

So this should work just like it did in the other cases

So let's go ahead and run this and it says enter your name. So my

You'll see it says your name is Mike. So that works out really

So for example, if I came in here, and I said enter your name, and

You'll notice that it's only saying your name is. John, it's not

Here's the problem. This is because

Whenever I use this scanf function and I use it with a string.

Space so once it sees this space it's gonna be like, okay, we're

So that's kind of a problem and that's just kind of how scanf

There is a way that we can modify scanf in order to be able to get

but there's another function which I want to show you guys which

it's similar to scanf but f gets is

Basically going to be more generous F gas is essentially just

It's not gonna be able to grab it and store it inside of like an

It's just gonna be able to store it inside of like a string of

When we're using a forgets the first argument

We want to give it is the name of the variable where we want to

So in our case, it's just gonna be this name variable

The next thing we want to do is specify how many characters we

So this will essentially limit the amount of characters that the

And this is always a good idea when we're trying to get a string

Enter in like a million characters and they would overflow the

Like see wouldn't be able to handle accepting that many characters

We can specify how many characters we want to be able to accept so

Because that's how many characters we can store inside of this

I'm just gonna say stdin and this stands for standard input

what we're doing over here is we're telling FCAT s--

where we want to get the information from and standard input is

Now I'm using F Gatz and this is going to do exactly what scanf

the input inside of this named variable, but now we'll be able to

Multiple words instead of just one single word. So let's run this

So now if we entered in John Smith

You'll see it's able to enter in John Smith

Now the one downside with just using this F gets is you'll notice

So let me actually demonstrate this a little bit

So if I was to print out like, you know, just some random text

Whenever I get input using scanf, so if I entered in John Smith

So when I'm entering this by clicking the Enter key that's

Inside of the string. So when I click enter you'll notice it says

And then it prints out a newline and it prints out this text

And so that's just something that you need to be aware of when

but for the most part, I would say if you're getting input from

A user in the form of a string you can use F gets you can also use

Percent asses and i'm actually going to show you guys how we could

But for the most part I would say whenever you're getting a string

Guess so that's the basics of getting input from the user

there's a couple other things that we can do and I'm gonna talk

At least one other way that we can get strings from the user in a

But this is kind of the basics and you can kind of play around

In this tutorial I'm going to show you guys how to build a basic

we're basically gonna build a little program where the user can

Our program will take those two numbers add them together and spit

So this is gonna be kind of cool and we'll also learn about

So over here, I want to show you guys exactly how we can do this

the first thing I want to do is

Print out a prompt. So I basically want to prompt the user for

Inside here. We're just gonna give them a little prompt. So I'll

Essentially what we're gonna have them do is enter in two numbers,

so we'll make an int and we'll call it num1 and

Then we'll make another inch and we'll call it num2 and i'm not

Values right up front we're gonna end up giving these whatever the

So after the user enters the first number we need to actually grab

In here, we're basically just gonna say percent d because we want

I'm going to say the name of the variable

Where I want to store the value that gets entered now if you're

We were able to get a string of characters as input from the user

And basically we just typed in like the name of the variable

But when we're getting input, that's not a string of characters

In other words when we're getting input that's not percent s so if

so if it's a guy a decimal or an integer or a float or a

special symbol this ampersand

So I'm gonna have to say ampersand and then the name of the

so I'm just gonna say ampersand 1 and

Basically what this means is we're accessing the address of num 1

but for now just know that you need this ampersand here in order

Store the value that gets entered inside of this variable

we're basically just gonna do the same exact thing but for the

I'll paste this and now instead of saying enter first number.

Second number and we're just gonna store this inside of num2

Alright, so once we're done with this, the last thing we want to

So I'm just going to come down here. I'm going to say printf and

We'll just say answer and over here

We'll print out the answer so it's gonna be an integer and we're

So we're gonna print out the value of num1 plus num2. So we have

We're getting the second number. We're storing them inside of

Let's try to run our calculator. So I'm gonna run my program and

So let's go ahead and enter 6 enter

A8 and now we're gonna get 14. So 14 is the correct answer

So our program worked it was able to add the numbers correctly and

But let me show you guys one problem with this program if I wanted

Multiple non decimal numbers, for example if I said 2 and then

We're not going to get the correct answer. We're gonna get 6 plus

Which is gonna be an integer 8, but we're not gonna get 8 point 8,

So instead of letting the user enter in only integers

Why don't we instead let them enter in doubles so over here?

I'm going to change these to double so I'm gonna say num one's

Since we're getting doubles as input, we're gonna have to come

So right now this is accepting an integer

but we want to make this accept a double so normally if we're

Printf and we wanted to print out a double we would say f and that

but when we're scanning for a number if we want to use a double we

LF just like that so down here. I'm also gonna say LF and we'll

so print F is a little bit different than

Scanf right and scanf if we want to accept a double as input. We

We just use % F. So let's run our program now and we should be

floating-point numbers so decimal numbers over here

I will do four point five plus six point seven and we get 11 point

Looks like everything is working properly. And now we have a basic

So the user can enter in any numbers that they want and the

Now this calculator is not like 100%

ironclad secure for example, like if I was to come up here and

Enter in like a string of characters instead of a number you'll

So it's just like not doing what we wanted to do

And as we go further in this course

We're gonna learn all sorts of ways that we can check to see if

circumstances like that, but for now, this is just kind of an

Addition or multiplication once we have them

In this tutorial I'm going to talk to you guys about building a

We're gonna be building a mad libs game now

If you ever played the game mad libs

it's basically a game where you write down a bunch of random words

You know nouns or verbs or someone's name or you know a verb

you take all of those words that you enter in and you kind of

Sprinkle them in into a story and then generally the story is like

It's actually if we head over to my web browser

You'll see I have a picture of a Madlib up here

And basically you just add in a bunch of random words into the

Kind of funny so I'm gonna show you guys how we can build

And we're also gonna talk about some more ways that we can use

So over here, we have a little story that I printed out. It just

I love you kind of like a classic poem

But I think this poem would be a lot funnier if we turned it into

So that's exactly what we're gonna do. I'm gonna replace roses are

So we're just gonna have a user enter in a color. I'll replace

So we're gonna have them enter in a plural noun, and I'm gonna

We're gonna say I love and then a specific celebrity. So I'll just

Alright, so this is basically what we're gonna be printing out

Plural nouns are blue and then I love whatever celebrity so let's

So we're actually going to need to do a couple things

And actually the first thing I want to do is I want to create

The color that the user inputs the plural noun that the user

we're going to create three variables and these are basically

character strings, so they're going to be

Collections of characters and we can store them in

Variable so I'm gonna create some of these variables. Why don't we

String or like a collection of characters?

We need to make these open and closed square brackets

And what I also want to do because I'm not gonna be giving color

I just need to tell see how many characters we want this

String to be able to store that way si knows how much memory it

So I'm just gonna say 20 and we'll basically just say they can

we're gonna do the same thing for plural noun and

again, we'll let them enter in 20 characters maximum and

Finally, we're gonna do the same thing for celebrity. So again 20

Alright now that we have our variables created. I want to actually

so I want to prompt the user for

Information and I want to take the information that they entered

First order of business is to prompt them for input so I can just

We'll basically just type in enter a color

Once we've prompted them to enter the color we can actually get

I'm going to use a function called

Scanf and over here. I'm gonna accept a

string so I'm going to accept a string of characters and we're

remember if you watched the last tutorial we use the

Ampersand here when we were getting numbers or also you'd do the

But when we're getting input for a string of characters, we don't

Let's copy these and I'm gonna paste this two more times

so the second thing we want to get from them is going to be the

plural noun and I'm gonna store this inside of the plural noun

Finally, we're gonna do the same thing for celebrity. And again,

Okay, cool. So now I'm getting the color. I'm getting the plural

So the last thing we have to do is we have to take all of these

Right, so we need to be able to print out the story with all of

So I'm gonna come down here and I'm just going to say percent s

Same thing here. I'm gonna replace the plural noun here with a

percent s and we'll pass in the

Plural noun and finally same thing for celebrity down here

Alright so everything seems to be wired up and you'll notice that

Lines, let's go ahead and run this program and we'll see how we

So over here, it's prompting us for a color. Why don't we enter in

Microwaves and enter a celebrity. Why don't we just say?

Prince so when I click enter it's gonna say roses are magenta

Microwaves are blue. I love prints. So we were able to prompt the

We took everything that they input we stored it in variables

Then we printed all those variables out inside of our story and we

I do want to show you guys one way that this program could mess

So let's enter in a different color. I'm going to enter in like

And now enter in a celebrity so I'm gonna show you guys one way

If I entered in a celebrity with a first and a last name like Tom

You'll notice that instead of saying I love Tom Hanks. It's only

Here's the problem when we use that scanf function scanf is only

Whitespace, so essentially when we put this space here. We're

but in reality we want to be able to grab the there's

Full-name want to be able to grab the celebrities first and last

So this is a situation in C where we would have to modify our a

instead of just getting one variable like the celebrity I can

Celebrity F and that'll stand for celebrity first name and then

We can make another variable called celebrity l that'll stand for

instead of just scanning for one string of characters I can scan

Down here. We're gonna want to do the same thing so we can just

Celebrity L and we just need to add another percent here

So it's gonna say I love celebrities first name and celebrities

so I can enter in like red and

Microphones and now we can enter in Tom Hanks and we're printing

So that's one way that we could remedy this program and make it be

And it also just shows you guys a little bit more about how scanf

It's gonna stop getting the input at that first space now

Here's the thing about this program though if I wanted to enter in

So if I only wanted to enter in one the program actually isn't

so if I said like hats and down here if I said

Like Gandhi and I click enter you'll notice that it's still

Right, so I could enter in something here and then the program

But it was waiting for me after I entered in just that one name

So that's something that you're gonna have to you know play around

Basically C is gonna force you to be very specific about what the

so if the user needs to enter two things like two words and you

Enter in one word. You have to specify that. So you have to be

In this tutorial I'm gonna talk to you guys about using a raisin

we're gonna be dealing with a bunch of different data and

one of the things we can do to control and manage and sort of keep

Put data inside of things called arrays an array is really useful

But what happens in your programs when you're dealing with huge

Specifically huge amounts of information that are related right

I had a list of like a bunch of names or a list of a bunch of

Let's say I had like a list of a hundred numbers, right?

I wouldn't want to have to create a hundred different

variables to store all of those different numbers and this is

Data structure where we can store a bunch of different data

So inside of an array unlike a variable where I can only store one

So inside of a single array, I could store like five things or

I could sort a bunch of different pieces of information and then

Organized in my program so I'm gonna show you guys how to create

Like we create a normal variable and a variable in array are very

variable is basically used to define a container that

Stores a single value and an array is used to define a container

So the first thing we're gonna have to do when we create an array

Information and the first piece of information is what type of

I could say int and now I'd be creating an array that would hold

If I said char, I'd be creating an array that would hold

Or if I said like double the same thing but for double numbers, so

And I'm just gonna call this lucky

numbers whenever I create an array

I always want to use a special little symbol and this symbol will

Variable we want to an array and it's an open and closed

Square brackets whenever I use these open and close square

We want to store multiple pieces of information

Now there's a bunch of different ways. We can create these arrays

the easiest one though is to just say equals and I can make an

inside of this open and close curly bracket

I can just start typing out some numbers that I want to put in

Now I can basically type out as many numbers as I wanted and I

Inside of this array so over here, I you know, I printed out six

You know, the only thing that's limiting me is how many I can

So you'll notice that I put in the piece of data so like 4, for

And then I put a comma and a comma is gonna separate all the

So we would say 4 is the first element in the array 8 is the

These are all considered to be elements

Inside of this array and what's cool about this array is it's now

So unlike a variable where we can only store one value now in this

so if I wanted I can print this out and I'm actually gonna print

remember, we're gonna print out a

Number and I'm gonna show you guys how we can access

specific elements inside of this array

So all of these numbers are stored in this lucky numbers array in

But the question becomes how do we access them? Right, how can I

well, I could say present' d so I'm gonna print this out and now I

so I'm gonna refer to the name of the array and when I want to

Close square bracket and inside of this open and close square

I want to put the index of the element that I want to access so

And I can access them by putting the index inside of this square

so if I wanted to access this for for example

I can put a 0 inside of here. And now when I run my program you

We'll be able to print out that for

So over here, I'm printing out four if I wanted to access this 15

I can put a two in here. So now when I run my program I'll be

so one thing you might have noticed by now is that we start the

Indexes and arrays at 0 so when I wanted to access this 4 instead

You might think that 4 would be at index position 1 because it's

but in C we start array indexes at 0 so actually the first

element this 4 is gonna be at index position 0 so if I was going

I would say like 4 is at index position 0 this 8 is at index

So that's gonna allow me to access all these elements inside of

Individually, so I could print them out just by referring to the

Another thing I can do is I can modify some of the elements inside

Let's say I want to modify lucky numbers in x position 1 so let's

so I don't like this 8 anymore so I can basically just assign this

I can make an opening close square bracket

we can say 1 and I can just set it equal to something else so I

Now when we print out lucky numbers 1 instead of printing out an

200 so let's go ahead and do that and run my program and you'll

200 instead of 8 so you can modify any of the individual elements

Inside the array just by referring to the index and really when

Conceptually an array is basically just holding a bunch of

So when I access lucky numbers 1 it's the same as me accessing an

It's just that you know, the array is holding potentially hundreds

So an array is a very useful structure, especially if you're

So, like I said, I could do this with an N

I could also do this with a double I could do this with a float I

But there's gonna be situations where you might not necessarily

So let's say I'm creating an array and I don't know what numbers I

So maybe I just like want to create it

I want to tell C that we need it but I don't want to necessarily

Well up here. We're basically saying lucky numbers that open and

But if we don't want to give it all that information instead

I can just put a call a semicolon here but inside of these square

I need to tell see how many elements that this array can hold so I

Like hey, this array can only hold like ten elements or this array

So let's say we wanted an array that could hold like ten elements.

Capacity of this integer array is 10 so it has the potential to

and what I could do is I could come down here and I can start

Lucky numbers 1 is equal to 80, right?

so I'm giving lucky numbers 1 of value and now over here I could

You'll see we're printing of 80

but if I try to print out for example lucky numbers 0 so the lucky

This is gonna give me a negative 2 which basically means that it's

Element inside of lucky numbers at index position 0 but if I

0 is equal to 90 and now when I run my program it's gonna be able

So it'll be able to get that value

You're just gonna want to give these arrays values up front right

You're not gonna necessarily know what's supposed to go in there

you still have to tell see how many elements the array is gonna

You still have to like rigorously defined like hey

This array can only hold ten elements and that's just so C is able

Elements, so that's kind of the basics of working with arrays now

I do want to point out one thing that we've been using in this

strings, so I've been creating character strings so I could say

Giraffe Academy or other times in the program we created

Like when we were making our little game

we created an arrays and I would just say like 20 and then I would

Put that information in here. This is basically a

String of characters. So anytime we create a string in C like if I

I called it like array whatever. This is an array

So we've kind of just been taking this for granted

Like I've just been calling this a string or calling it like a

But it's basically just an array of characters

The only difference is this is such a common thing to use in our

C makes it a little C makes it special and makes it really easy

But just like that array of integers. This is also an array

So now you kind of have a better understanding of what strings are

I'm going to talk to you guys about functions in C a

Function is basically just a collection of code that performs a

So what you can do is you can take a bunch of code, you know

maybe like five or six or twenty lines of code and put it inside

Code that's inside the function

You can call the function and generally when you create a function

So the function will have a specific purpose

so I'm gonna show you guys how to create functions how to work

like I said a function is basically just a collection of code

Does a specific task so we can actually create a function here in

Now you'll notice up here. We have this block of code

It says int main and there's an open and closed parenthesis and it

and we've kind of just been using this for the entire course like

Just been kind of using this main little block of code here. But

Sometimes you'll hear people will call this a method as well. So

Essentially mean the same thing, but you generally in C. We're

But this is called the main function and the main function is

Basically a function that's gonna get executed when we start

And so we've already been using a function this main function, but

So make sure you guys have to do that

So let's go down and we're gonna go here outside of this function

The function is we're outside of this ending curly bracket. So

I'm going to create a function and when we create a function

We actually have to give C a couple pieces of information

The first thing we have to tell C is the return type of the

And so actually we're going to talk more about return type in the

But for now just know that return type is basically the type of

So sometimes your function can actually give information back to

We're just gonna say void and void basically means that this

That's the first thing that you have to tell see the second thing

And generally when we're naming a function, we're gonna want to

So in our case, we're gonna create a function that says hi to the

So I'm just gonna call this function say hi because that's what

Whenever I create a function now

I want to make an open and closed parenthesis and I'm gonna make

Code that goes in between these curly brackets. It's going to be

So let me show you guys I'm just gonna make this a very simple

We're just gonna make a printf and we're gonna print out hello

So I've created my function it's called say hi and inside of this

So now let's go ahead and run our program and see what happens. So

But you'll see up here that hello user doesn't get printed out

But this didn't get printed out and this is the first lesson with

Inside of the function we have to call it

Calling a function basically means we're telling C that we want to

So if I want to execute this code I can

And the way that I do that is just by typing out the name of the

So now instead of just printing out nothing C is actually going to

Function so let's run our code and you'll see now we're printing

So the difference between this main function up here and this say

this main function basically gets called but then if we want to

Functions we can call them from inside of this main function and

So also I want to show you guys one other thing. I just want to

The flow that these functions take I want to show you guys how

So I'm printing out top and I'm printing out bottom and I'm

So now I'm gonna run my program again and you'll see we're

And then we're printing out hello user then we're printing out

Lines, but essentially what's happening is when C goes to execute

It's gonna execute this first line of code printf

So it's gonna print out top then we're telling C that we want to

Function C is now gonna jump over here to the say hi function and

So in this case, we just have one line of code, but I could put

So if I have like five lines of code, it would execute all five of

Then it's gonna jump back up here and it's gonna move on to the

And that's sort of the basics of writing functions anytime

You have a block of code or a bunch of code that does one thing or

Encapsulate into its own little container that you can call

You can put it inside of a function and then whenever you want to

You just call it, but these functions can actually do a lot more

So one thing we can do is we can give these functions some

Information so I can actually give this function a piece of

This is what's called a parameter and a parameter is basically

So let's say in this say hi function instead of just saying hi to

We want it to say hi to someone specifically

I can actually come down here in these parentheses and I can

Parameter and I can specify a parameter a lot like I would specify

name and an open and closed square brackets

and I'm basically what I'm saying down here is this say hi

Parameter in other words as an input a string

called name and what I can do is I can come down here and I can

Percent s and we could print out name

Over here when I call this say hi function because I specified

I have to give it a string so I could give this a string like Mike

when I call this say hi function now, I'm

Passing the value Mike into this function

So Mike is gonna get stored inside of this name array and we're

Let's go ahead and run our program and you'll see it says hello

We're able to customize what it says

The cool thing about this is I could copy this line of code

Like I could call this function a bunch of times with different

So this is more obvious so I could say hello Mike. Hello, Tom

It's saying hello to each of these different people

because we define the function and we can pass it different names

Depending on what we pass it depending on the parameter that we

You can also specify multiple parameters. So let's say in addition

And then down here I can specify int age. And now we're basically

So I could say hello and then I could say you are and we'll say

So now over here instead of an addition to just saying name we can

Function and when I call it I have to also give this an age so we

70 and now this is gonna print out all that information for us. So

Hello, Oscar, you're 70 and you can pass as many parameters as you

You always just have to make sure though that you're passing a

When you're calling the function just like that. So that's the

This guy over here, which is the return type and we're gonna look

I'll talk to you guys about return statements in C

Where a turn statement is a special line of code that we can

back to whoever called them so I can write a function and that can

information back to whoever called it that could be information

It could be it a message telling whoever called it how the

Basically how we can do that and I'll just give you an overview of

I'm actually going to create a function and we're gonna create a

Cubes a number so when you cube a number generally you take it to

So I could say like 2 raised to the third power

Which is the same as just saying 2 times 2 times 2 this would be

You're taking it to the third power

So I'm gonna make a function that's gonna do that

This function will accept one

parameter which is gonna be a number and it'll cube that number

That value back to the caller and you guys will see how that will

So I do want to point out one thing whenever we are

Returning values in our function. So if you're gonna write a

You always want to put it above the function that's going to be

So for example like this main function down here, this is the

So any code we put in here is gonna get executed first if I want

I'm gonna define the function here above the main method and

It'll just make sure that everything works correctly

So we want to make sure that we define this function before we

so the first thing that I need to tell C when I want to create a

What type of data I want to return if you've been following along

You'll know in the last tutorial

We use the void return type which basically means we weren't going

But now we want to actually return information

so why don't we return a double and you can put any datatype here

Character or character array, but let's just do double and we're

So I'm gonna call this cube and I'm gonna make an open and closed

We're gonna allow this method or we're gonna allow this function

So it's just going to be another double and call it num. So

Basically, what we want to do is we want a cube num and we want to

Here, I'm just gonna create a variable

It's just gonna be another double called result and I'm gonna set

Times num times num. So basically this variable result now

represents or now stores the cubed value of num

all we need to do to return this value now is just say

Result and this return keyword is basically gonna do a couple

The first thing it does is it breaks us out of the function. So

It's gonna break us out of the function and it's gonna return this

So down here we can actually call this function

so actually what I want to do is I want to print out the answer

Answer and we'll print out the answer. So percent F

so I'm using % F because we're expecting to get a double back from

Over here. I can just say cube and we'll pass in a number. Let's

Essentially what's gonna happen now is we're going to call this

All this code is going to execute and this function is going to

3.0. So normally like in the past in this course what we wanted to

76 or you know, whatever we'd have to put a number right there

But we can just call this function because eventually this is

So this will contain a number after the functions done being

So I can actually just run my program now and this is going to

3 cubed is 27 3 times 3 is 9 9 times 3 27 so looks like our cube

Let's try with another number. Why don't we do 7?

So let's run this again and we get 343 I'm guessing that's right

So basically what we did is we created this function and we use

The value of cubing the number and that's really cool

And actually we can make this a lot simpler so I could actually

Result variable and I could just straight up return

Num cubed and this is and this is gonna do the same exact thing so

And one thing I want to point out is this return keyword will

So if I came down here and I said like printf and I printed out

This actually this code is actually never gonna get executed. So

You'll notice that it's not printing out here. So that never gets

Print out here. This never gets touched because when we use this

This breaks us out of the function. So whenever C sees this return

down here to the normal program

So just keep in mind that you can't

really put any code after you use this return keyword because it

You guys about one more thing really quick you'll notice up here

I'm creating my cube function above the main function. So I

and the reason that I did that was because if I was to move this

you'll notice that we're getting an error over here and actually

Conflicting types for cube now

Essentially what's happening is when I create this function down

When the main method over here tries to call it. It actually

like it doesn't necessarily know like what this function is what

Created it after we created this main method. So what I can do is

Prototyping and when I prototype it'll allow me to create this

without getting this error and basically when you prototype I'm

Function signature, so we would call this like the signature

So if I was to put this up here and put a semicolon

You'll see that we're not getting this error anymore, and we're

So this is a way that you can create functions below that main

basically any functions that I created I could put another

In this tutorial and talked to you guys about if statements in C

Programming structure which we can use to help our programs to

So in certain circumstances, they can do certain things and in

They can do other things and if statements are

Extremely powerful and they're a great way to add some

We're gonna be building a function. So we're gonna build a

Basically what this function is gonna do is it's gonna take two

two numbers and it's gonna tell us which number is the biggest so

Ten and it'll tell us which number is bigger. Let's go ahead and

It's going to return an integer and I'm just gonna call it max and

so it's gonna take an integer num one and it's gonna take another

Now we'll just make the actual function body

so inside this function our job is to figure out whether num one

To return the biggest to the caller

so the first thing I'm gonna do is create a variable and it's

I'm not gonna give it a value right away

What we need to do in this function is we need to figure out which

we need to figure out if num one is the biggest or

We need to figure out if num two is the biggest and this is a

To use an if statement an if statement allows us to check a

And if that conditions true we can do one thing and if the

I'm basically just gonna say if and then we're gonna make an open

Inside of here inside of these parentheses. We need to specify a

This is something that's either gonna be true or false if the

We're gonna execute the code inside of these curly brackets. If

In order to tell whether or not num1 is bigger than num2 or num 2

Num 1 and I can use this greater than sign

Num2. I'm basically saying if num 1 is greater than num2

then I want to do something so down here we can set result equal

This condition is true. Then we're gonna do this. So only when

num, 1 is greater than num2 are we gonna set result equal to num 1

Tell which one is bigger but here's the thing what if num 1

Greater than num - what if num 2 is greater than num 1?

I can use something called an else statement so I can come down

I don't actually need to use an open and close parentheses

I can just make an open and close curly bracket

And the code inside of this else block is going to execute if the

so if this condition is false if num 1 is not greater than num 2

Set result equal to num 2 and then down here. Finally. We're gonna

Result so depending on whether or not this is true

result is either gonna set equal to num 1 or it's gonna be set

So let's go down here into our main method and why don't we call

printf and we're gonna be printing out an integer and

Over here, I'm gonna call this function. So I'm just gonna say Max

So we're passing a 4 it will pass in a 10

So I'm passing in a 4 and I'm passing in a 10 and this is going to

Other words this should return 10. So let's go ahead and run our

So we got the value of 10 back from this function. Let's try it

So let's make the first number bigger. So now we have 40 and 10

So this should give us 40 back awesome so over here we have an

We're basically checking to see if num 1 is greater than num - if

Num2 and it's important to note that even if I made these equal

So if I made it forty and forty, we're still going to get back the

So it's still gonna give us forty back. So this is the basics of

We say if we specify a condition if that conditions true

We're gonna execute this code if that conditions false

We're gonna execute this code down here

And that is an extremely powerful structure in our programs and we

So depending on what the user puts in num1 and num2 we can do

But this is just sort of the beginning. So why don't we try to

So down here we're allowing the user to input two parameters

So we're accepting two parameters into this max function num1 and

But let's up the ante a little bit what if we wanted to accept

So instead of just passing in two numbers

We wanted to be able to pass in three numbers and have the max

This max function, so I'm just gonna make another parameter. So

So now this function is accepting three parameters num1 num2 and

But in order to figure out which one of these is the biggest we're

So I'm gonna get rid of this and let's just start from scratch. So

How can we figure out which one of these is the biggest?

well, what I would recommend is we could say if num 1 is greater

Num, 1 is greater than num 3 then we know num ones the biggest

So if num1 is bigger than num2 and it's bigger than um

3 we know it's the biggest if num2 is greater than num1 and num2

Is greater than num 3 then we know num2 is the biggest and

3 is the biggest so I'm gonna show you guys how to do this and

Concepts for if statement so I'm just gonna say if and I want to

so I basically want to see if num 1 is greater than

or equal to num 2 and num threes so down here I can say num one

Greater than or equal to num2 and now I also want to check to see

Because if num1 is greater than or equal to num2 and it's greater

We know num1 is the biggest so I can use this special signal here.

Basically, this is going to allow us to put another condition in

basically what this and does is it allows us to put two conditions

This whole thing is only going to be true if this conditions true

So if one of these guys is false, then this if statement isn't

I'm just gonna open this up and if this is the case that we want

equal to num 1 because if num 1 is greater than or equal to num -

Num, 1 is also greater than or equal to number 3 then we know num

We also want to check to see if num 2 is the biggest

We also want to check to see if num 2 is the biggest now we can

I can make another open and closed parenthesis and inside of these

So if this stuff up here at this conditions false then else if is

So here I want to do basically the same thing

I'm gonna check to see if num 2 is greater than or equal to num 1

Num 2 is greater than or equal to num 3

So if this condition is true if num 2 is greater than or equal to

Then we know for a fact that result is gonna be num - because

We can just say else and we can make another to open and close

And remember this code is going to get executed when neither of

So here we can just set result equal to num 3

So let me walk you guys through this one more time up here

We have this if statement and in addition to checking to see if

we're also using this special operator called and and we're

That's the case then result is going to be equal to num 1

Otherwise if this condition is false

Then we're gonna come down here and we're going to check this

So we're gonna check to see if num 2 is bigger than num 1 and if

3 if that's true, then we're gonna do this

Finally if neither of these conditions up here is true

We're just gonna go ahead and set result equal to num 3 and then

Let's test this out and we're gonna see if it works. So now when

This is basically going to spit out the biggest one, which should

Let's run our program and you can see over here

we get 3 so let's try to make one of the other ones the biggest so

Biggest and let's run this again and you can see that it returns

So that's how we can use these ands and we can also use else--if

so the and is used to check more than one condition inside of the

Parentheses and the else if is used to check another condition

Now I want to show you guys a couple other things

There's a couple other things that we can do with these if

I'm gonna come down here and just show you guys some of these

In addition to using that and we can also use something called or

I'm just gonna type out a simple if statement I could say if

3 is greater than 2 and instead of using and like this I can use

Check two conditions, and the whole thing is going to be true

if only one of those conditions true so I could say if 3 is

So only one of these is true, right 3 is greater than 2 that's

but 2 is not greater than 5 so this guy's false, but when we use

One of these two conditions has to be true for the whole thing to

Now when I run my program we should print true because we're using

But if I was to make this guy false, so if I made this 3 less than

It's not gonna print out true and we can just print out false. So

Now we're gonna end up renting out false because both of these

So you can see down here. We're saying false. So the difference

Both of these conditions have to be true in order for the whole

When we have or only one of these guys has to be true

so that's kind of the difference there and I want to show you guys

Over here we're using like a less than sign

If 3 is less than 2 I can also use a greater than sign I could use

Could use also a greater than or equal to sign and if I wanted to

I could use a double I could use a double equals

So the double equals will check to see if 3 is equal to 2 we can

exclamation point an exclamation point basically means not equals

3 is not equal to 2 then we'll print out true so down here. Let's

So yeah, there you go. One more thing. I want to show you is how

Operation. So for example, if I said 3 is greater than 2 this is

so we'd end up printing out true down here because 3 is greater

I could surround this whole thing with

Parentheses and I could put an exclamation point right before this

Whatever this ends up being so this is true

And we put this negation operator here this whole thing is going

Because this is true and we're using the negation operator. We're

And you can see we just don't print

But if I put a false condition in here, like if I said three is

This is false. But because we're negating it now, it's gonna end

So when I run my program you can see that we get true

So that's sort of the basics of using if statements and I cover

We can use ands, we can use all these different comparison

We can use ORS and we can use this exclamation point to negate

In this tutorial I'm going to teach you guys how to build a

You'll know that in the beginning of the course. We actually

We let the user input two numbers and we took those numbers we

I'm gonna take some of the stuff that we've learned since then and

functional for function calculator

So this calculator will be able to add

Subtract multiply and divide and we're gonna let the user decide

So we'll let them decide if they want to add or subtract or

it's gonna be pretty cool and we're gonna end up using some of the

statements we're also gonna use like getting input from users and

Input from a user as well. So down here. We want to start making

What I'm gonna do is I'm gonna ask the user to enter a number

Then I'm gonna ask them to enter an operator like plus minus

we're gonna ask them to enter in a third number and then we'll

Depending on what operator they specify so addition and

So the first thing I want to do is create

Variables where we can store the numbers and the operator so I'm

Num 1 and then we'll make another double call it num2

finally, we'll make a variable that will store the operator that

Operator. All right. So now we want to actually get input from the

I want to figure out what numbers they want to use and then what

So down here. Why don't we get some input?

The first thing I'm going to do is I'm just gonna print out a

And now what we want to do is we want to be able to

Take the number they give us and store it inside of one of those

So I'm just gonna use this scanf function

Scanf and in here I'm gonna specify that we want to get a double

So remember when we're using scanf if we want to scan for a double

F and L F is going to scan for a double and now I'm going to use a

Variable that we want to store in here

so I'm gonna use this ampersand and I'm just gonna say num 1

So this is exactly what we need to do to be able to get the users

The next thing we want to do is get the operator. So I'm gonna

They'll be entering in plus sign minus sign asterisks or forward

and again now we're going to scan for a

Character now when we're scanning for a character and scanf and

We want to do something special. So I want to put a % and a C. But

I want to put a space so whenever we're getting a character from

Right here before % c otherwise, it's not gonna work. And again we

One more time we're gonna get another number. So I'm just gonna

We're gonna get this one for num2

So now we should have all of the input for our program. So I'm

I'm getting the operator and I'm getting the second number. The

So we're gonna have to figure out which operator they wanted to

Right, so we have this Opie variable and this is storing like a

So depending on what that's storing we want to print something

Different out so we can actually use an if statement to do this so

What operator is inside of our operator variable and depending on

Operation so I can say if and the first thing I'm going to do is

If the operator that the user entered is equal to a plus sign then

So I'm just gonna print out these two numbers and I'll just say

Because we're gonna add both of them together. We can also use an

So I'm going to want to check a few other conditions

I'm going to check to see if the operator is equal to a

Sign and if the operator is equal to a minus sign then instead of

I'll just copy this and we'll paste this guy down here

So it's going to be num1 - num2

And I can actually just copy this whole thing and we'll paste it

We'll paste this other elsif and here we're going to check to see

So we'll check for a forward slash. And again, we're just going to

Decimal number so it's going to be num1 divided by num2

Finally, we're gonna check for multiplication. So if it's

So now we're checking for each of the operators. We're checking

But here's the thing what happens if the user enters in an

so for example if they don't enter in any of these operators

We're gonna want to tell them so I'm gonna have this like print

We're just gonna say else and basically the code inside this else

If none of these conditions up here true and down here we can just

So now we have our if statement or if block setup and this should

Alright, so let's go ahead and run this program so you can see

It says enter a number so we can enter a number. Let's enter in

Enter an operator we'll add numbers and now let's enter in 4.0

So we're gonna add five point nine and four

so when I click enter we should go through all of those if

Statements and figure out what we need to do and you'll see over

And we're getting nine point nine. So looks like the program

Why don't we try to multiply some numbers? So let's multiply

Times I don't know five point seven so we get thirty four point

All right, and then one more time we'll run this and I want to try

So we'll say like 5.7 and I'm just gonna enter in a G. So that's

That's not going to work and I'll enter my number. Let's do 8 and

we have a four function calculator this calculator can multiply

Add and if you don't enter in a correct operator

It's smart enough to yell at you and tell you that you have an

This seems to work pretty well. I'm pretty happy with it

And you can see down here like this is a perfect situation for

We have this variable opie, right? It's storing some sort of

We don't necessarily know what's inside of there

But I can use if statements and I can respond to the different

So in the situation where it's a plus sign I can respond in the

And this just makes our programs a lot smarter and it helps us to

In this tutorial I want to talk to you guys about using switch

now a switch statement is basically a

Special type of if statement which will allow us to compare one

And it's essentially doing the same thing as an if statement

It's allowing us to check different conditions and if different

Then we can do certain things but a switch statement makes it

specific value to a bunch of other values now

I'm gonna show you guys how we can use that in this tutorial to

So I'm gonna build a little program that will take a letter grade

It will tell you whether or not you did good or bad on a test

So if you got an a on the test it would say hey you did a good

If you got a B on its house, it'd be like hey you did

Alright, if you got an F on the test to tell you that you failed

so we're basically gonna have a variable where we'll store a grade

Respond to that grade using a switch statement. So it's gonna be

the first thing I'm gonna do is create a variable and it's just

So we're gonna say that whoever took this test got an a on the

Now what I want to do is I want to create a switch statement. So

Switch and I'm gonna make an open and closed parenthesis and

I'm gonna put grade so I'm just gonna put grade and I'm gonna make

So this is sort of like the basic structure for our switch

I'm gonna take this variable here that I pass into the parentheses

So I'm gonna take this I'm gonna see if it's equal to one value

then I'm gonna see if it's equal to a different value or a

Depending on the value that it ends up being equal to we're gonna

cases so down here I can say case and

Character so for example, I could put a right here and then I'm

and when I put a right here, basically what this is saying is the

then I'm gonna put some code down here that I want to execute so I

I could say like you did great

because they did great on the test and

what this is saying is in the case that the grade is equal to a

Which is called break and I'm gonna explain what break does in a

So I could make one of these little case statements for every

so for every possible grade that we could get so I'm actually just

So now I can put a B in here. So we're saying in the case that the

I'm gonna say you did. All right, and

Then we're also going to break and down here. I'm gonna make

So I'll say case and this time we'll make it C in the case that

There's a couple more that we can check so we can check if they

I forgot to put a break statement here and I'm gonna put one down

And finally, we're just gonna do one more for if they failed the

So I'm just gonna say in the case that they got an F

Essentially, what I'm doing here is I'm writing out all of these

So I'm saying in the case that you got an F. I'm gonna print out

I'm gonna print out you did very bad

And then we also have this break statement here and this break

So whenever we're executing this switch statement whenever C is

It's checking to see if grade is equal to each one of these cases

So for example, let's say the grade is equal to a it's gonna

But if I don't put this break statement in here, then it's just

So it's always important to put a break statement in there because

I don't want to be in here anymore. So finally we can check one

Or that we get an invalid grade. So for example, if someone

G or something that's not a valid grade so I can use something

Default is basically like an else so default is going to execute

whenever none of these conditions up here or Matt so then I can

Invalid grade or something and this will basically be like, hey,

So let's take a look at this switch statement and we'll just kind

Basically, I'm passing this in a variable or a value or something

all of these different conditions

We're gonna print you did great and the case that B is equal to

and this is basically doing what an if statement doing so I can

An if statement I can write out if etc else--if else--if else--if

But this just makes it a lot easier

So I don't have to constantly write out all of that if statement

So hopefully we did everything right and let's actually check and

So grade is equal to a let's run our program and see what our

It says hey, you did great because we got an A if I made this an F

Now it should tell us that we failed

So it says you failed if I made this a C

It'll tell us that we did poorly and it says you did poorly

So this is a super easy way for us to check one single value

And that's really the point of a switch statement is you're

Against a bunch of other values and that's where it can be

So consider using the switch statements

They're not appropriate in every situation and there's I'd say

But when they are appropriate switch statements will save you a

I want to talk to you guys about strux in C now a struct is a data

so inside of a struct I could store like an integer alongside of

String alongside a character alongside a double I could sort all

Structure and there's tons of uses for structs and one of the

So I could basically like a model

Something in the real world inside of my program and I'm gonna

We're gonna be looking at how we can use a struct to represent a

So imagine we were writing a piece of software that was using like

I could use a struct to represent a student in my program so over

I'm just gonna come up here above the main method and I'm actually

and how we can use them so I'm just gonna say

Over here, I'm gonna give this a name so I'm gonna call this

Student and a lot of times in C when we're making structs. You're

Capital letter just like that and I'm gonna make an open and

Inside of this struct I can start specifying what types of data

So basically I can define like different attributes of a student

And this will kind of act as a template and you'll see how we can

So let's think about different attributes of a student

Well one thing would be like the student's name so I could say

so this is gonna represent the name and actually why don't we give

String can hold 50 characters maximum and now we're gonna make

So we're gonna want to store the students major and again, we'll

I also want to make an integer for the students age and

So I have this struct student and in here

I have a bunch of after buttes of a student right have like the

An integer that stores their age and a double for their GPA

Essentially what I did was I created like a type of student data

So I basically am allowing myself now to represent a student

so let's come down here to this main method and I'll show you guys

Create an instance of this student structure so I can create like

Inside of my program and the way that I do that is just by saying

Struct and I want to type out the name of the struct that I want

It's gonna be a student and I want to give this a name. So I'm

I can just use a semicolon here

basically, what I did now was I created a container called student

Name a major in age and a GPA

So if you're familiar with arrays in C, you'll know an array is a

But all the pieces of information inside of an array needs to be

Struct I can have a bunch of different data types like this and I

So now let me show you guys how we can assign some values to

So for this particular student student 1 I can give them a name

I can give them a major a GPA and an age so I could say

student 1 dot age and I can set this equal to something so I could

Inside of this student 1 container I'm saying the age of this

I can do the same for the GPA so I can say student GPA is equal to

So I'm saying this particular student's GPA is a 3.2. I can also

So for the name and the major now, here's the thing about working

Remember in C a string is actually just an array of characters and

We can't like give it a particular value

So for example, if I wanted to give this students name of value,

So I can't just come down here and say student name is equal to

That's not gonna work because you can't do that with an array

I can use something called the string copy function and this is a

String and it'll give it a value that we specify so it'll

with the age and the GPA but with the name so I could say like

Str. C py and inside of here. I need to pass this two parameters

The first thing I want to pass is the destination for the string.

student 1 dot name the second thing I want to pass in is the

String that I want to store inside of student 1 name. So in our

So now we have the student 1 names value is equal to Jim and I can

so I'm just gonna copy this and we'll come down here and I could

Business, so let's say Jim is a business major

Essentially what I've done here is I've created a student and that

so this particular student had a name a major in age and a GPA

So I assigned this student 1 an age of 20 to a GPA of 3.2 etc

So now what I can actually do is I can print out all these

so if I wanted for example, I could like

Print out the GPA so I could print out

Student 1 GPA and now we're gonna be printing out

3.2. And actually it looks like I have a typo here. This should be

Alright so here we're printing out 3.2. So we're printing out the

I can also print out like their name. So why don't we do that

So you see we prints out over there

So a struct is a really useful structure

And another cool thing we can do with structs is we could actually

Student so I could create like another instance of that student

I'll show you how we can do this. I'll just come down here and

Instead of student 1 why don't we call this one student 2 and we

Let's say their name is Pam and they're studying art

So now I have a completely different student

And if I wanted I could print out this students attributes so I

Dot name and now we're gonna get Pam instead of Jim so you can see

So I could create as many of these students as I want and this is

Structs is I can just define the basic template for a student in

Individual students down here that I can work with. So now I have

I could do whatever I want with it. I could pass it into a

I could print it out onto the screen

I could use it in something like an if statement I could do

It's it acts a lot like a variable or an array

so remember variables and arrays or just

Containers we can do just about anything we want with them and

so this has just been kind of an introduction and

What you could do as an exercise is think of other things you

So maybe something like a book or something like a phone you could

Information you could store using a struct just like this

In this tutorial I want to talk to you guys about while loops in

now a while loop is basically a structure in the C programming

Continually execute a specific block of code until a certain

So I can specify a condition and then I can basically just loop

there's a lot of times in our programs or we're gonna want to let

Continually do something while something else is true or while a

Is met and I'm gonna show you guys a really basic while loop in

We're actually gonna build a really cool guessing game using while

And you should get a pretty good idea of like how these things

And this isn't directly related to creating a while loop though is

So I'm just gonna create an integer called index and I'm gonna set

What I want to do is I want to actually create a while loop and

So in order to create a while loop

I can just type out while and open and close parentheses and then

And this is basically like the outline sort of like the template

Basically how this is gonna work is up here in these parentheses

I'm gonna specify a condition and as long as that condition is

I'm gonna loop through all of the code inside of these curly

So inside of these curly brackets, I'm gonna put a bunch of code.

I'm gonna execute all that code so

Up here. We're going to specify a condition. I'm gonna specify a

5 so while index is less than or equal to 5, I want to execute all

So I'm gonna put some code in here. The first thing I'm going to

I'm just gonna say we're gonna print out an integer and

I'm just gonna print out index so we'll be printing out index and

Finally after this. I want to increment the index variable so I

Basically, I'm adding one onto the index every time and actually I

Situations where you're gonna want to do something like this

there's actually a shortcut we can use so I can come over here and

This is gonna do the same thing. So this is just gonna add one to

Essentially, what I'm doing is I'm saying I want to print out

Through this code while index is less than or equal to five

So let's go ahead and run this program and maybe you can predict

You'll see over here. I'm printing out the numbers one through

So I'm printing out one two three

Four and five and let me walk you guys through exactly what's

we create this index variable and we set it equal to one and

Basically when C goes to execute this program the first thing it's

does anything else is it's gonna look at this condition and it's

Or equal to five. Well, the first time through index is equal to

It's gonna execute this line of code printing out one

Then it's gonna execute this line of code incrementing index

Then what C's gonna do is it's gonna come all the way back up here

so it's gonna say okay is index less than or equal to five and

Index at this point is equal to two so it's less than five

so it's gonna go through execute this line of code execute this

C's gonna go all the way back up to the top it's gonna check this

So before C goes through this loop

It's always gonna it's always gonna check the condition first. So

It has to check the condition to make sure that it's true

Eventually, we're gonna get to a situation where index gets

then C's gonna come back up here and it's gonna check to see if 6

False and we're gonna move with our lives in the program and

So this seems very simple and that's because it is all we do is

As long as that condition is true

We keep doing all this stuff in here and there's tons of

This is just one of them where we can print out like numbers

I also do want to point out one thing

That you might want to watch out for which is called an infinite

Where this condition up here never becomes false

So this condition will just always stay true and there are certain

But in a lot of circumstances, you're not gonna want to go

So let me just demonstrate so you guys can see so if I stopped

Now when I run my program you'll see that it's just continually

I mean look at all these ones that are getting printed out you can

This program is just it keeps executing through that loop and it's

So this would keep going forever if I let it keep going

but that'll kind of show you like how an infinite loop works and

you'll get into situations as you work with while loops where

That especially if you're doing something a little bit more

Slow your computer down quite a bit. So this is a while loop and

there's also one other type of loop that's similar to a while loop

Before I do that, I just want to do something really quick. So I'm

I'm gonna set this equal to 6 and I'm gonna run my program and

so the code inside of this while loop

Isn't gonna print out because the first thing we always do when we

So the first thing C's gonna do before it prints anything before

It's not gonna do any of this stuff

So when I run this program, you'll see nothing's gonna get printed

There's another type of a loop that's similar to a while loop

Which is called a do-while loop and I'm going to show you how to

All you have to do is take this wild thing up here and paste it

A do-while loop is similar to a while loop

But the first thing a do-while loop does instead of checking this

So even though index is equal to 6

we're still gonna print out 6 and we're still going to increment

Then we're gonna check the condition to see if we can keep

So let me show you guys this and this should illustrate what this

We're printing out 6 so unlike before when we just use that while

We're doing whatever was inside of that loop before we're checking

Come in handy. I would say by far while loops are way more common,

Loops because there are certain circumstances where they'll come

Basically any time you don't want to be checking the condition

But those are the two basic types and there's actually another

Which is called a for loop, but for now

We're gonna have some fun with while loops and in the next

I'm gonna teach you guys how to build a little guessing game and

This is gonna be pretty cool because we're gonna use a lot of the

In order to build it, so let's get started basically

This guessing game is going to allow the user to guess a secret

so we're gonna define a secret number and we're gonna give the

opportunity to try and guess it so if they'll try to guess it if

They don't get it right then

Right, so we'll basically let them keep guessing what the secret

We want to create a couple variables

The first variable I want to create is gonna be an integer and

So I'm just gonna call it secret number and why don't we just set

We want to create is gonna store the user's guess

so this is also gonna be an integer and I'm just gonna call it

Right off the bat. The user wouldn't have guessed a number

So what we want to do is we want to be able to prompt the user to

Right. So as long as the user hasn't entered in the correct

We want to keep asking them to enter it in in order to do that in

Enter it until they've guessed it and we can use something called

So I'm just gonna type while and when making open and close

Let's think about a good condition for our game, basically

We want to keep asking the user to enter an input as long as they

So it's right there we could keep looping as long as the guess is

and basically this is always going to be true until

They guess the correct number now inside of here

we want to prompt them to enter their guests and then we want to

Store it inside of our guest variable. So let's do this first

Scanf in order to get whatever number they enter and I'm gonna

inside of that guest variable so I'm just gonna say at guess and

Or whatever integer they enter and it's gonna store it inside of

So basically what's happening in this loop is every time through

getting a different number and then we're gonna come up here and

It's not then we're gonna go through again and we're gonna keep

But if the guest is equal to the secret number, then we'll break

So I'm just gonna print out a success message and I'll basically

All right, awesome so you can see this isn't actually that many

I mean, it's probably like ten lines of code to write out this

So this should actually work properly. So let's try to run this

So remember a secret number is five

So I'm gonna run the program it says enter a number. So let's just

three so you'll notice I can keep entering in numbers and

It'll keep prompting me to enter a number as long as I haven't

And remember five is the secret number when I click enter now that

Because the guess is gonna be equal to the secret number and it's

So we broke out of that loop we executed the print statement that

Terminated and that is a really cool little game

so one of the cool things about this game and

It's different from programs that we've written in this course in

Essentially infinitely until we enter in that correct guessed

So it's gonna keep going and keep going keep asking us to do

Until we entered correctly. So this is pretty cool now

This is a pretty nice game and it's it's pretty simple

But I want to maybe make it a little more complex one of the

Is that the user gets unlimited guesses, right?

So basically like they can just guess every single number and

So why don't we do this? We should impose a guess limit

So why don't we say like the user can only guess three times and

Then they'll lose the game. So let's think about how we can go

Into this little app, I'm gonna walk you guys through how we can

The first thing we're gonna need to do is we're gonna need to

variables I'm going to create another variable up here and I'm

Guess count is basically going to tell us how many times

the user has tried to guess the secret number and I'm just gonna

Initially, the user will have guessed zero times

so remember this guest count variable is basically gonna get

Right, so I'm gonna come down here. Every time we go through this

So every time we go through this loop, I'm gonna increment the

Guest count plus plus and that means every time the user guesses

The guest count will get incremented and we'll have a accurate

the second variable that I want to make is

Going to be another integer and I'm just gonna call it guess limit

Can guess so this will basically determine like how many guesses

So why don't we set this equal to three?

I think three guesses is a pretty good limit and finally we want

variable and this is also gonna be an integer and I'm just gonna

guesses and I'm gonna set out of guesses equal to

zero and out of guesses will basically

Tell us whether or not the user has any more guesses and this

But keep following with the video and you'll see how this comes

So we're actually gonna have to modify our code a little bit so

So the user can keep guessing as long as the guess isn't equal to

But we want to be able to limit the amount of times that the user

I'm going to create an if statement and every time we go through

I want to check and see if the user has any more guesses left. I

I want to see if they've reached their guessed limit so I'm gonna

Long as the guest count is less than the guests limit

That means they haven't guessed as many times as the limit

Basically, they can guess again, right so down here inside of this

I'm gonna put all of this code and I'm just gonna surround this

so basically the user can only guess the number this code will

Guest count is less than the guessed limit when the user has

Additional guesses right when they haven't guessed as many times

Otherwise though, so if they have guessed too many times

Right if the guest count is either equal to or greater than the

I'm actually gonna set this out of guesses variable equal to one

Basically what this is going to tell us is if out of guesses is

Then that'll tell us that the user is out of guesses. So

Essentially if out of guesses has a value that's more than zero

we'll know that they've run out of guesses and

If you ever use any other programming languages before this is

It's basically storing like a true or a false value, which we're

So if the guest counts less than the guessed limit they can guess

Otherwise we're gonna say out of guesses is equal to one. In other

There's one more thing we have to do though is we have to come up

Condition because right now we're gonna keep looping through this

But there's actually two situations where we want to break out of

The first is when they've guessed the number correctly

Right, then. We want to come down here and print out you win

But we also want to break out of the loop when they've run out of

So I want to check to see whether or not they're out of guesses

so I'm gonna say guess is not equal to secret number and

So as long as out of guesses is equal to zero

That means that they're not out of guesses and they still have

But if the guest counts less than the guessed limit and out of

Then out of guesses isn't going to be equal to zero anymore. So

So basically, there's two scenarios now that will break us out of

They get the word right or they run out of guesses

So one more thing we have to do in this program is come down here

We're always printing out you win. So no matter what like no

We're printing out you win and that's because before if they made

That means that they guessed the secret number correctly

There's actually two scenarios

Down here where they would have broken out of the loop where there

So I want to actually check to see which one we're dealing with.

Of guesses and I'm gonna check to see if it's equal to one and if

That means that they lost and they ran out of guesses. So I'm just

otherwise though, it means that they won so I'm gonna say

You win and this will basically be like hey you won the game

I know that and let's just run this see how we did

And we'll see if our games working properly and then I'll kind of

And actually you know what? I just noticed the typo down here. I

This is just have to be a single equals. So we're assigning this

I had two equals that needs to be one. So let's go over here

We'll run our program and it says enter a number. So why don't we

I'm just gonna say two two and now we're on our third and final

That means we're gonna lose the game

So I'm gonna enter and you'll see it says out of guesses

So we weren't able to guess it within our three tries and the game

Let's run it one more time. We'll try to win so I'll say like two

We're on our third and final guess

So if I don't get it this time

we're going to I'm gonna guess of five and we guessed right so

Basically how this little program works and I'm gonna walk you

so we have all these variables up here secret number is

Just storing the number they need to guess the guest keeps track

The guest count is gonna tell us how many times they've guessed

guess limit is gonna tell us how many times they can guess and

Out of guesses is going to tell us whether or not the user is out

We're checking two conditions for this while loop. We're checking

We're gonna keep looping as long as out of guesses is equal to

We check to see if the guest count is less than the guessed limit

If it is then we ask them to guess we increment the guest count

Otherwise we say out of guesses is equal to one and that's gonna

the first situation is that they ran out of guesses the second

We're using this if statement to check both of those

so that's basically how this works and this kind of shows you how

variables together in like one single program

In this tutorial I'm going to teach you guys how to use for loops

now a for loop is a special type of loop that we can use in C

indexing variable and this indexing variable will basically tell

iteration of the loop we're currently on and we can use that

Loop through an array of items we could do all sorts of stuff

You'll see that I have a while loop

Set up and I have just sort of a basic while loop and I want to

Essentially up here I'm saying int I is equal to 1 so I'm giving

I the value of 1 and I'm saying wow I is less than or equal to 5

I'm gonna print out the value of I and then I'm gonna increment I

basically, we have this variable I and every time we go through

Greater than 5 so let's run this program and we'll see what it

So you'll see over here. We're basically printing out values

so the first time that we go through this while loop we're

The second time we're printing out to the third time. We're

Basically telling us what iteration of the loop are currently on

so on the first iteration of the loop I is

telling us that we're on the first iteration of the loop, right

Second time we go through the loop

I is equal to 2 third time I is equal to 3

So this variable I over here is basically telling us how many

So on the third time, it's telling us 3 fourth time for etc, and

This is actually a very useful thing for us to have when we're

It's there's a lot of situations where you're gonna want to know

when you're looping so with a normal while loop like I can

You can kind of just do whatever you want with it

but in a lot of situations and there's tons of these situations

That will tell us what iteration of the loop that we're currently

Basically just a variable that's gonna keep changing every time we

situation in see that there's actually something called a for loop

Condense it into its own single loop. So it's taking this

It's basically allowing us to do it a lot easier and a lot

So I'm gonna show you guys how we can create a for loop

I'm gonna come down here below this while loop and I'm gonna

So I'm just gonna say for I'm gonna make an open and closed

the difference between a for loop in a while loop is

Basically gonna happen inside of these parentheses. So in the

Right. This is specifying whether or not we can keep looping

We're gonna have three different things. So instead of just one

We're actually gonna have three different things that we want to

with a for loop the first thing I'm gonna put in here is

This variable I so you'll notice in the while loop

we have our variable I up here and this is basically

Allowing us to loop through and keep track of how many times we've

So what I can do down here is I can do something similar I could

I'm gonna say I is equal to 1 so basically I'm gonna take my

Of 1 and now I have my I variable I have my variable that's gonna

The next thing I want to do is include my looping condition so up

We have I as less than or equal to 5, that's our condition. I can

So I'm gonna say I is less than or equal to 5

The third thing I want to do is increment I so you'll notice down

Every time we go through this loop, we're incrementing that

So you'll notice I have these little like sections. Here's the

We're initializing the very I were saying I is equal to one

Here we're specifying our looping conditions

so i'm saying we're gonna keep looping while I is less than or

Over here is a little line of code. That's gonna get executed.

So here I'm saying I plus plus I could also say like I minus minus

I I could say like I is equal to I plus two

Etc. Like I could do basically anything I wanted over here. Let's

so you'll see I was basically able to take all of this code and

Instead of having to like print this out and create this variable

Inside of this for loop now, I can basically take this line of

I can paste it down into here and we essentially have the same

So right now this block of code and this block of code are 100%

They're doing exactly the same thing

So let's go ahead and get rid of all this code and let's test out

So I'm just gonna run my program and you'll see over here. We're

We're printing out one two, three, four five. So it's the same

doing the same exact thing and that's why for loops are great

Structure like where we have an indexing variable and we can use

so I want to show you another situation where these four loops can

We can use them to loop through all the elements inside of an

I have this array that I created. It's called lucky numbers and

We have this lucky numbers array. It has 4 8 15 16 23 42 and

What I could actually do is I could loop through all of the

From this for loop so I'm gonna show you guys how we can do that

Let's first off see how many elements we have

we have 1 2 3 4 5 6 so we have 6 elements in this an array so

what I'm gonna do is I'm actually gonna say I is equal to 0 and

Second but basically array indexes start at 0

So this first element in the array is at index position

zero and just for a little refresher if I wanted to access one of

Was zero and this is going to give me access to this element

If I said lucky numbers two, then I'll get access to this element

So this is basically how we can access an element inside the

so I'm gonna set I equal to zero and I'm gonna say I want to loop

Six was how how many elements we had in the array?

So I want to keep looping as long as we're less than six and I'm

Now down here. I'm gonna do this same exact thing but instead of

So I'm gonna print out the array element at index position. I and

Basically the first time we go through this loop

We're gonna be printing out lucky numbers zero

Because I is going to be equal to zero the second time we go

We're gonna be printing out lucky numbers one because I is gonna

And we're gonna keep doing that

Until we get all the way up to five which is gonna be the last

So let's go ahead and do that. So I need to put this back to I

Let's run this program. So you'll see over here

We're basically doing exactly what I said. So the first time

We're printing out that first element the second time through the

15 16 23 and 40 - so we're printing out all of those elements in

There's a lot of situations where for loops are gonna come in

but this is a very very very very

common situation where we want to loop through all the elements in

You know do something to them, whatever

so that's the basics of working with for loops and I do just want

Anything that you do with a for loop you could do with a while

I basically showed you guys how we transform that while loop into

Convenient so it makes it really easy to do something like this

In this tutorial I'm gonna talk to you guys about two topics in C

Two-dimensional array is basically a situation where we have an

The second thing I want to talk to you guys about is nested.

So we're gonna look at how we can use a looping structure where we

Inside of loops. It's gonna be pretty cool

and actually these two topics can go together really well and I'm

Two-dimensional arrays in order to make an awesome program. So

the first thing I want to show you guys is

two-dimensional arrays so down here

we can create a 2d array and actually the concepts that I'm

Multi-dimensional arrays so not only two dimensions but three four

So in order to create a two-dimensional array, I'm just gonna make

So I'm just gonna say int and we'll give this a name. So why don't

Normally when we create an array after we'd say the name of the

But when we create a two-dimensional array

we're gonna make two open and closed square brackets just like

Width and the height of our array so you guys will see what I mean

but basically we're gonna have like

Elements in the array and then each of those elements is gonna be

So these two squares will allow us to like manipulate all that

An open and closed curly bracket now, this is normally how we

So normally I would just say like 1 2 3 4 whatever I could put all

But with a two-dimensional array all of the elements are gonna be

Arrays inside of here. So for example, I'll put an array right

so for example the first element in this array, I could just make

So you can see here. I have two elements

Inside of this array which is itself the first element of the nums

We'll come down here and we'll make another one and this keeps

So now we're gonna say three four

So this thing right here this whole array, that's the first

Right and that array has two elements inside of it. Same thing

This is the second element in the numbers array and it has two

So this is going to be five six

So now we have three array elements right one

Three and each of them has two elements inside of them

So whenever we create a two dimensional array like this

We always have to specify the number of elements and then the

so in our case, we're going to have one two three elements in the

Each array has two elements inside of it

So it's gonna look like that so we would say three and then two

So now let's talk about accessing these elements. So I'm gonna

We're gonna print out some of this stuff. So I'm gonna

Say % D and I'm gonna show you guys how we can access individual

So basically I'm gonna say nums and let's say that I wanted to

the first thing I want to do is specify the index where

The value that I want to access is stored

So like this would be index position 0 this would be index

then I want to specify the index position of the

individual element inside of 0 so I could say like this is element

So I print out nums 0 0 and this is gonna print out that

Numbers coming out. It's gonna print out that one for us. You can

So let's try a different one. Let's try to grab this for right

One and then one so this would be at 1 1 and now we should get

so that's basically how we can access elements inside of these

if I didn't want to give this an initial value

I could just like put a semicolon here and I could just like

Manually define each index location so I could say like 0 0 is

like I don't have to give it a

Value like right up front although in our case. Let's just do that

All right, so we have our numbers array and we figured out how we

So now I want to talk to you guys about another

Concept which is called a nested for loop and you guys will see in

but a nested for loop is a situation where we have a for loop and

inside of that for loop we have

Another loop so I'm gonna show you guys this really quick. Let's

I'm gonna create two variables over here in I and int J and

I don't know if I showed you guys this in the course yet

But if I want to just like declare two variables

I can just say I comma J and that will declare both the variables.

We're gonna do that inside these four loops

So I want to show you guys how we can use a nested for loop in

inside of this two-dimensional array, so I'm gonna say for I

and we're gonna keep looping as long as I is less than

Three and the reason I'm saying three here is because that's how

so I'm gonna keep looping as long as I is less than three and then

Now inside of these curly brackets, I want to create another

loop, so every time we go through this one iteration of this top

J is less than 2 and the reason I'm saying 2 here is because

Inside of the nums array and you guys will see in a second. Why?

this is gonna work and then I'm gonna say J plus plus so now I'm

Down here. I'm gonna actually be able to print out all of the

So I'm gonna go ahead and do that

I'm just gonna say printf and we're gonna be printing out an

and I'm gonna print out nums I and

So whatever the value of I is and whatever the value of J is

inside of nums that we're gonna print out and now just so this is

Formatted a little bit better. Why don't we put a comma?

Right there and then I'm also gonna put another printf over here

And you'll notice that this printf is outside of this inner for

We're gonna see what it does. You guys will see exactly what's

And you'll see over here when we ran the program

We're basically getting this entire 2d array printed out. So I'm

So let's talk about why that happens

Over here I'm saying for I is equal to 0 I is less than 3 I plus

So I'm going through this particular four loop three times

I'm gonna execute all the code inside of this four loop right

Three times that's as many times as there are elements inside of

Now every single time I go through this top loop every single time

I'm going to execute this loop in its entirety. So I will loop

I'll go through all of its iterations and this loop says J is

2 over here is how many elements are inside of each one of these

So this element in the noms array has one two elements inside of

This element in the numbers array has one two elements inside of

That's where this two is coming from

Then I'm incrementing J. And I'm gonna print out so I'm saying

so the first time we go through this for loop I is going to be

Remember that first time we're actually going to be going through

So we're going to be printing out nums 0 0 and nums 0 1 and then

the next time we go through this I loop we're gonna come down here

Finally the third and final time. We're gonna print out nums to 0

That's basically how this is working. So

Nested for loops are a match made in heaven and there's a lot of

Where you know besides just looping through 2d arrays that we're

But hopefully this gives you a little bit of a introduction into

I'm gonna talk to you guys about accessing memory addresses in C

Now in the C programming language a lot of times we're gonna want

Right, and there's a bunch of different ways that we can store

We can use things like variables we could use arrays we could use

but the basic point is that whenever we're using c we're gonna

Maintain a bunch of different pieces of information and one of the

Variables so down here you'll notice that I have a bunch of

I have this integer called age and it's just has the value of 30

We have this double GPA 3.4 and we have this character grade and

I have a bunch of different

variables in my program and it allows me to keep track of data

You know maintain and I can even modify these different

But I want to talk to you guys a little bit about how these work

So whenever I create a variable for example when I create a

And I give it a value of 30 this value 30 actually gets stored on

Memory, so a lot of times you'll hear people refer to this as RAM

It's called random access memory and basically RAM is the memory

So for example, if I was to run this C program my computer would

It would use that memory in order to store and keep track of all

Right. So when I create a variable like int age C is actually

Location so it's gonna take that value 30 and it's gonna store it

C's gonna take this value 3.4 and it's gonna store it inside of

C is gonna store this character on the physical memory in our

Now here's the thing when I create these variables I give them

So I know what's stored inside of it, right?

And when I want to access this value, I can just refer to the

I can just refer to age I could modify and I could print it out

I could do something else to it

I can do whatever I want with it and the way that I can access

variable in other words the way that I can access the value 30 is

Just by referring to the name of the variable same goes down here

Right if I wanted to access this capital a I could just refer to

All of this information is stored in our physical memory

And so whenever C needs to access that information whenever our

3.4. It's actually going to refer to a specific memory address

Right. So when I want to access this variable age, I can just type

But when C wants to refer to this value, it's not actually using

It's gonna use the memory address where this value is stored

So all of these values are stored inside of a physical address in

So all of these values have an address where they're stored in

So I'm gonna show you guys how we can access that address how we

And basically just wanted to give you guys an introduction into

I'm gonna say printf and I'm gonna show you guys how I can

Where each one of these values is stored on our computer?

So down here if I want to print out a memory address. I need to

normally if I was just gonna print out like a number I could say

Character when we want to print out a physical memory address

We're gonna say % P and this actually stands for pointer. We're

We're just gonna talk about memory addresses

But just know that you need to say % P and now I'm going to type

I want to access so I'm gonna access the memory address of age

Before the variable. I'm just gonna say

so I'm gonna make an ampersand age and I'm gonna say percent P

Now we should be able to print out the memory address where the

In other words, we can print out the memory address where this

You'll see over here. We're getting this number

So I'm getting this number 0 0 6 0 FF 2 0 0 so this would be like

I guess it's not technically a number. It's like I think it's

But basically this is the physical memory address where the value

It's the place where C stored the value inside of this age

I could do the same thing for these other variables

so actually why don't I format this a little bit I'm gonna stay

again, I'm gonna print out another one of these addresses and

so now I can just come over here and I can sort of modify this a

Grade and you'll notice for each of these I'm using this ampersand

So now when we run our program we should get a nice little list of

variables and their corresponding addresses so you'll see over

have age and it's stored up memory address 0 0 6 0 FF OC

GPA is stored at this memory address and grade is stored at this

so if you were to like go into our computer or go into my computer

Go to memory address is 0 0 6 0 FF 0 C that's actually going to

30 it's gonna store the value that's inside of that age variable

If you were to go to this memory address you would see the value

Inside of GPA if you're going to this memory address you would see

so basically all of these variables are store at

Different memory addresses when I want to access the information

I can just refer to the variables name so I could say a age or I

But when C wants to access the information and the variable it has

Addresses so C would use this address C would use this address and

I can just use the variable names and that's why C is awesome

But when C and when our computer wants to access these values it

and so that's why these are useful and

it can actually be pretty useful to be able to know the

Addresses like the actual physical addresses of these certain

So a lot of times in C when we want to work with these

Variables we can just refer to them by name and we can do all

We can access them we can modify them. But in other circumstances,

We're also gonna want to be able to access their physical memory

we're gonna want to be able to know like what that address is and

In future tutorials, I'm gonna talk about why that can be useful,

I really just wanted to kind of give you guys an overview of what

How we're using them in our program and how we can print them out

I just use this ampersand and then I type the name of the variable

In this tutorial I want to talk to you guys about pointers in C

Now a pointer is basically just a type of data that we can use

So up until this point in the course, we've been using a bunch of

we've been using things like integers and an integer is just a

decimal number we've been using

Chars and a char is basically just a character and now I want to

which is called a pointer and a pointer is basically just a memory

you know a physical address inside of the memory of our computer

Storing a value right and I think pointers

Tend to confuse a lot of people who learn about them and this is

Because it's you know, traditionally very confusing to understand

Extremely simple and the problem is that they just get over

So what I want you guys to do is I just want you guys to think of

That's all it is. It's just a type of data that we can work with

It doesn't have to be any more complicated than that, right?

I can work with an integer in my program an integer is a whole

I can work with a double in my program a double is a decimal

I can work with a char in my program a char is just a character

I can work with a pointer in my program a pointer is just a memory

That's it. A pointer is just another type of data that I can use

Inside of my programs and it just happens to be a memory address

It's very simple people overcomplicate pointers and they don't

Just like an integer or a double but instead of being like a whole

So hopefully that makes sense and I hope you think you guys don't

Try to over complicate this too much because it doesn't have to be

I have an integer that I've created and it's called age. So I just

Inside of this integer. I'm storing a whole number

I'm storing an integer right third

And if you've been following along with this course in the last

We talked about memory addresses and we talked about how all of

Physical addresses on our computer's memory so down here

I have this print statement and I'm just printing out ages memory

Ampersand age and we talked about how this ampersand when I put

It's going to give me the physical address in memory where this

Thermia value is stored. So if I run this program you guys will

Hexadecimal number right? This is the physical memory address of

What did we just talk about before remember what I told you

Memory addresses that's what they are

it's a type of data a pointer is a type of data in our program

It's a memory address right when I use this ampersand and I type

This is giving me the memory address right I'm able to print out

This is a type of data in our program. That is a memory address

That's a whole number and a double is a type of data. That's a

That's a character a pointer is a type of data. That's a memory

This guy right here is a pointer. So it's just the memory address

and when I want to print out a pointer I can use this percent P

It'll allow me to print it out onto the screen and everyone's

So essentially what I'm doing here is I'm printing out a pointer

I'm telling this print F function that I want to put on a pointer

It a physical memory address. That's what a pointer is now

We understand and hopefully understand that a pointer is just a

We can access the memory addresses of specific variables by using

The name of the variable and that can be pretty useful

Now that we understand that I want to show you guys how we can

I have an integer variable called age and this integer variable is

I'm gonna say that one more time. I have an integer variable and

I could also create a double variable so I could create a double

Inside of this double variable. I could store a double value like

Called grade and inside of this char variable. I can store a

could also create a pointer variable and

Inside of that pointer variable I could store a pointer

So just like I stored a character inside of this character

I could store a pointer inside of a pointer variable so we can

Now here's where this is going to get a little bit tricky

When we create a pointer variable

we actually need a physical memory address right so when I create

Integer variable like I can just come up with a number right off

I can just say like 30 when I create a

Double variable I can just store whatever number I want to store

but when we create a pointer variable remember

We're gonna be storing a memory address and I don't necessarily

Know any memory addresses like right off the top of my head at

So when I create a pointer variable, what I want to do is store

That's already in a program. So I'm gonna say that one more time

inside of that pointer variable

I'm gonna store the memory address of a another variable inside of

so let's say that I wanted to create a pointer that would store

This variable over here so thats or the memory adjusts of age,

can create a pointer just like this so I could say int and

asterisks and now I'm gonna give this a name so I'm gonna give

Pointer variable a name and remember this pointer variable is

variable and generally when you're naming a pointer, you're gonna

Then you're gonna type the name of the variable whose memory

So I'm gonna say P age right because this pointer variable is

Now what I want to do is set this equal to the memory address of

Which we can access using this ampersand so I could say ampersand

so now this pointer variable is

Storing the memory address of the age variable

I'm gonna do the same thing down here for this GPA

So if I wanted to create a pointer variable that would store the

asterisks and I'm just gonna say P GPA just like that and I'm

This double variable which we can access using this ampersand and

I'm gonna do the same thing down here for this character variable

So I want to create a pointer variable which is going to store the

The character variable so I'm just gonna say char

grade, and I'm gonna set this equal to

Ampersand grade. Okay, so that's all I'm doing, right?

So now I have this integer variable and I have this pointer

Which is storing the memory location or the memory address of the

I have this double variable which is storing a double and I have

The pointer just happens to be the memory address of the GPA

I have this char variable down here

And then I have this pointer variable, which is storing a pointer

the physical memory address of

the great variable in our memory

Okay, and that's basically all you need to know about pointers to

It's just a type of information that we can work with in our

it just happens to be a memory addresses write an

integer is a type of data that we can work with in our programs

double is a type of data that we can work with in our programs and

char is a type of data that we can work with in our programs and

Pointer is a type of data that we can work with in our programs

Hopefully that makes sense and just like we create integer

Pointer variables the only difference is whenever we create a

We're gonna store the memory address of another variable in our

So so you'll see over here when I create this pointer variable.

The variable whose address I'm storing so over here when I'm

When I'm storing the address of a double variable I'm saying

I'm saying char here and that's the basics of using pointers and

Also creating pointer variables and storing memory addresses

In this tutorial I want to talk to you guys about

Now a pointer is basically just a type of data that we can work

So sometimes in our programs we're gonna want to work with memory

We're gonna want to use them in our programs and do certain things

pointers in our programs and when you dereference a pointer

Essentially what you're doing is you're going to the memory

Pointer and you're grabbing the piece of information from there.

So all points are as our memory addresses and when we dereference

We go to that physical memory address and we get the information

so I'm gonna show you guys how we can do that and see it's

Down here. I have this integer and

It's an integer variable and it's storing the integer value 30 and

memory address of 30 so it's storing the memory address of our age

Down here. I'm just printing out this pointer

So I'm printing out pH I'm using this percent P and I'm just

So why don't we take a look and see what we get. So you'll see

We just get this memory address probably exactly what you expected

I want to show you guys how we can dereference a pointer

So this pointer variable P age is storing the memory address of

We basically were given the physical memory address where this

So P age is storing the memory address of 30. It's storing the

Inside of our computer's memory if I want to dereference a

Basically, what I'm gonna be doing is I'm going to be going to

So the way that I can dereference a pointer is by using the

So when I'm printing this point, I can dereference it by using

But now over here since I'm dereferencing this pointer

I need to print out a number instead of a pointer because when I

This is no longer a pointer. This is no longer a memory address

This is gonna be whatever was stored at the memory address. The

Variable was storing the address of an integer

Right, so when I dereference it

This is actually gonna be an integer

So let me show you guys I'm gonna print out or I'm gonna run our

So you'll see that we get a 30. So basically what's happening here

Pointer variable we're dereferencing the pH pointer which

Physical value that's stored at the memory address that the

And that's basically what dereferencing is, you know, you're you

You can dereference it and you basically just get the value that

It's essentially all we're doing so I want to show you guys how we

Just normally so for example

I have this age variable if I just typed this out

If I wanted to get the address of this age variable I could use

That's basically what we did up here

but what I could do is I could just dereference this so I can say

asterisks here and this is actually gonna

dereference that entire thing

So now when I run my program it's gonna print out 30, so it's not

It's just gonna print out 30 so you can see over here. We get 30

so I could actually do this like as many times as I want and this

An ampersand here and now I'm gonna get that memory address again

So you'll see we're getting this memory address and I can do the

You'll see now we're getting that 30 value again

I mean basically what I'm doing I'm constantly like like here I'm

Then I'm dereferencing and getting the value then. I'm getting the

So, you know, hopefully that makes sense when you dereference a

you're basically just getting the value that that pointer is

memory address of the pointer

In this tutorial I want to teach you guys how to write two files

One of the cool things we can do in C is we can actually modify

So in this tutorial, I'll just basically show you guys how to do

We'll talk about creating files writing files and appending on to

So let's go ahead and do that down here in my main function

We're actually gonna create a file. So I'm going to create a file

the way that we can do that is we can just type out file all in

essentially what we're doing here is we're creating a pointer to a

I'm just gonna say file and I'm gonna make an Asterix and I'm just

So I'm just gonna call this F

Pointer and that'll just stand for file pointer, and I want to set

Open an F open is actually a function that's gonna open a file for

And so inside of these parentheses, I'm gonna give this a couple

The first parameter is gonna be the name of the file that I want

employees dot text and the second parameter is gonna be a

File mode and a file mode is basically just going to tell C

What we want to do with the file that we're gonna open

And there's a bunch of different file modes. The three most basic

So if I put R in there, I mean we want to read the file

W stands for right so if I put right in there

it means I want to either create a new file or write over an

There's also a which stands for append and that means I want to

we're gonna look at W and a so what I want to do over here is

Right now employees dot text. This file doesn't actually exist

So what I'm gonna do is I'm actually going to create that file

We're gonna put some information inside that file and then that

We're gonna need this write mode

So it's just going to be a W

Anytime that we're open file in see you always want to make sure

I want to use another function called F close and

Basically what this is going to do is it's going to close off the

so it's gonna remove the file from the memory on our computer and

if we do make any changes it'll kind of like save the file and

Everything will just be kind of like locked in so you always want

It and inside of this F close function. We just want to pass in

Pointer right there. So let's talk about what's happening here

Essentially like a data type I guess and we're creating a pointer

So if you remember a pointer is basically just a memory address

Right a pointer is a type of data that we can use in our programs.

this pointer is storing the memory address of this new employees

Essentially what's going to happen is we're gonna create this

Pointer is going to be pointing to the memory address of that file

So that's essentially what's happening here. And what I want to do

To this file. So actually let me just show you guys really quick.

So without doing anything else just using this line right here

Employees dot text is going to get created so over here

I'm in my little directory and

If you don't specify an absolute path or like a relative path for

It's just gonna create it in the directory that your C files in

So if I wanted to create this on my C Drive, I could say like C

Whatever and then like employees out text and this will get

Or even if I don't specify a relative path

then this is just going to get created in the same directory as

My main dot C file is right here. It's in this folder

So when I run this program, let's watch over here and we can see

So I'm gonna run my program and you'll see over here that this

So if I actually bring this out a little bit you'll see it's a

Its employees dot tax and there's zero kilobytes inside of this so

But this file got created. So now let's talk about putting some

I'm basically just gonna list out a bunch of like employees that

The easiest way to write information to a file is just to say F

Print F and this is a special

Function in C, which actually works a lot like the printf

So if you've used the printf function and if you're following

We've been using it throughout the entire course the printf

Printf is it can allow us to essentially just write information to

I need to give this a couple parameters. The first one is gonna be

I need to tell this function, you know what it should be writing

Then over here we can just give this some information so I can

Can just use this like I normally would the printf function so I

So I could say like let's say one of the employees is Jim

And we'll put like what they do. So like I can say sales men and

then we could say actually let's make a new line and we'll create

receptionist and then we can make some other employees so

So now I have three employees that I'm going to basically write

We can go over here to this employees file

You'll see when I open this up that we have these three lines in

So we have Jim salesman Pam receptionist and Oscar accounting

So basically I was able to create this file and write all this

Information in the file from down here just from down here in this

And I want to show you guys with right so when I'm using this,

This is actually going to overwrite a file. So for example if I

Overridden in here now when I run this program and

We open this employee's dot text file. So let me reopen this

You'll see it just says overridden so I've actually overridden all

And that's basically what happens when we just write to a file. So

I'm just gonna run this again. So we have this text

And you'll see now we're back with the employees so let's say that

We wanted to add an employee on to the end of it

So we wanted to add like a new employee on to this file, right?

Well, I can use something called append and what append is gonna

To the end of this file or actually just append text on to the end

I'm just gonna say a and you'll notice I'm still keeping employees

another employee into the file

The first thing I'm gonna do is print out a new line because and

There actually isn't a line after this last line so the last like

I can't actually get on to the line below Oscar

So I'm gonna want to go ahead and print a new line and this will

Kelly and she's gonna work in customer

Service. So now when I run my program instead of overriding what

This is just gonna append this new employee onto the file. So I'll

And let's open this employee's file and you'll see now we have

We either create a new file and add content onto it or we just

At least using this F printf function and when we append, we're

so just using those two things, I mean you can

essentially write out any you want

and it's important to note that you can write more than just text

HTML file or I could write like a CSS file

you could write really I mean any type of file that you'd want

That's basically how we can write to a file and append it to the

I will not teach you guys how to read the

Information from a file in C in the last tutorial we talked about

So we looked at how we could create a file overwrite a file and

I'm gonna show you guys how you can read

Information from a file so down here you'll notice that I have my

So I just say file and the asterisks and I'd called it FP and

this is just a pointer which you know and a pointer is just a

Memory address and it's the memory address of this file in

Memory, so it's the memory address of this employees dot txt file

Opens this file and then I'm specifying a file mode

We talked about the W file mode and the a file mode now

I want to talk to you guys about the our file mode and this stands

So when I use the our file mode

I'm actually able to read information from the file and this can

So in order to read the information in the file

I'm actually going to show you guys how we can read like the

So actually first let's look at the file

This is employees dot txt. It just has you know, basically a bunch

We're gonna be able to read this file inside of our program

so the first thing I want to do is

create a variable and I'm gonna create this variable up here

it's just gonna be an array of characters and I'm just gonna call

I'm gonna give this an initial size of 255 so be able to store 255

Order to read this file. I can actually read the file one line at

Gets and F gets basically is going to allow us to read the lines

Gets and I need to give this a few different parameters the first

I need to give it is a place to store the information that it

So this function is going to go and it's going to read the

So the first parameter we need to give this function is where it

We're going to store it inside of that align variable that we

size and this is basically just gonna be like

The maximum size that we can read in so I'm just gonna say 255.

Then we also want to give it that file pointer

Pointer and basically what this is gonna do is it's going to read

Inside of this line variable. So if I was to come down here and

Just print out line now when I print out a line

It's actually going to be have the value of the first line in the

You'll see over here. We're printing out Jim salesman

And if you didn't remember that was the first line inside of that

So basically what F gets is doing is it's reading the first line.

Essentially pointing to where the file is in our memory and

So it's basically gonna move past the first line in the file

So if I was to use this again?

For example if I said f gets again

It's gonna store the value of the first line of the file inside of

And when I use it again, it's now gonna grab the second line in

This should actually be storing the second line in the file. So

Receptionist I can basically do this for all of the lines in the

So that's basically how we can use F gets to read the individual