Original subtitles

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All right guys, it's time for yet

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another code challenge to test and see if you've learned what was covered in

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previous lessons. So head over to the assignment

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that is a day 3.1 odd

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or eve. Have a read of the instructions and try to see if you can create a

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program that checks whether if a number that you input in the console is odd

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or even. Now the thing to remember here though

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is that we're introducing something called the modulo

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and you can create the symbol by simply typing the percentage sign. Now,

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what the modulo does is it will divide a number

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say seven by another number

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let's say two, and then it will give you the remainder of that division.

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So seven divided by two, seven split into portions of two is two plus two plus

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two plus one, right?

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So seven divided by two can be divided three times with a remainder of one.

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And that's what the modulo gives you.

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So you can also type code straight into the console like I'm going to do now;

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7 % 2. It gives me 1.

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Now it's the same thing if you try to divide by other numbers,

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let's say 7 % 3. Well,

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that is three plus three plus one, right?

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So seven modular three will also give me one.

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So this is a way for us to divide a number by another number and get the

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remainder.

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And you're going to be using this modular to solve this code challenge.

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Have a read of the instructions,

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have a look at the examples and see what it is that we're expecting to be

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printed in the console here.

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And then go ahead and write your code and see if your output matches what it is

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that we're expecting. So 56 should be even,

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so you should be printing "This is an even number" based on that input.

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Pause the video now and give this code challenge a go.

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All right.

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So I mentioned that the modulo gives us the remainder, right?

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So what do we know about even numbers? Well even numbers they're always divisible by

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two. If we pick any even number, say 54,

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and then we do modulo two, so 54 divided by 2,

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it should always give us zero

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as long as that first number is even so 68 % 2

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again it zero.

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But then when we come across an odd number, say 53 % 2,

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then this is now going to give us 1.

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We can use our code to check for when the result is zero,

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in which case it's a even number. And when the result is one,

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in which case it's an odd number. If you have gotten stuck until this point,

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and this is a really great time to pause the video again and go back and give it

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another go. And then we'll go through the solution together.

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We can simply write an if statement to check if the number that was inputted is

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divisible by two with zero remainder.

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Well, in this case, then we can pretty much be sure that this is an even number,

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because as we've shown, all of the even numbers when they divide by two,

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there's always no remainder. So in this case, let's add a colon.

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We can print pretty confidently that this is a even number.

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Now,

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what about the cases where the number when divided by two is not equal to zero?

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Well, then it's probably going to be an odd number. So in this case

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we can use an else statement to catch that.

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And when we have an odd number, we'll simply print

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this is an odd number.

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So that's it. Just four the lines of code using what we've learned about if, else,

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and also the comparison operator. Now,

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if you got stuck on this and you needed to watch the solution,

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then I recommend really going back to your code and playing around with it so

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that you can get the code to work. And then try and see if you can test if a

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particular number is cleanly divisible by three by four by five,

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and then see if the final program actually works in the way that you expect it

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to. But once you're ready,

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head over to the next lesson where we're going to talk about even more complex

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ways of using if and else statements. So for all of that

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and more, I'll see you there.