All language subtitles for 009 Object Oriented Programming in Dart_en

In the last couple of sections, we took this code snippet right here and pulled it apart line by line,

and we've now got a better idea of some of the very basics of the dart language, including variables

a little bit on types and a little bit on functions as well.

In the section.

We're going to start to move forward and start to look at one of the absolute core concepts of the dart

language, which is object oriented programming.

DART uses object oriented programming or OPIS as a paradigm or style for writing code and designing

applications.

With OPIS, we build our applications out of a collection of objects.

An object contains some amount of data relevant to our application, like these pieces of data over

here stored inside of what we call fields or properties.

This data is hidden away from other parts of our application.

The only way to get access to this data right here is through the use of methods which are functions

that are defined directly on this object.

One thing that I want to point out here is that we're using the term object to refer to this thing that

contains some amount of data.

But in DART, you and I are going to work on something just a little bit different.

So kind of a different piece of this puzzle.

So in Dart, you and I are going to create what are called classes.

A class contains a set of rules that define how it works.

You can think of this class right here as being like a blueprint or a ruleset of sorts to actually work

with this class.

We create instances of the class which referred to as either objects or instances.

So a class is just a set of blueprints, whereas an object or an instance represents a real working

copy of that class.

To recap, you and I write code to create classes.

We then use that class to create objects or instances.

A good analogy here between classes and instances is to think of a set of blueprints that might be used

to build a house.

When you first want to get a house built, you would go to an architect and have them put together a

set of blueprints that describe how the house is going to look and function.

After you get that set of blueprints put together, you can then use it to create an unlimited number

of houses or instances.

So in this analogy, as you might guess, the set of blueprints over here is like the class and the

actual built house or the actual standing house that physically exists in front of you would be like

the class or something.

The object or the instance.

Now, in darte, object oriented programming is something that comes up nonstop again and again and

again, so much like types that we were taking a look at earlier, it's something that we're going to

be discussing throughout this course many different times.

If you've ever worked with object oriented programming before, you're going to be in good shape if

you've never touched it.

You're also going to be just fine.

So one of the later projects that we're going to work on inside this course before before we even start

working on Flutter is going to be intended to give you a rock solid footing in object oriented programming.

So you're going to get a lot of experience with it.

Now, let's continue in the next section.

We're going to start talking about how we put together classes in DART and some of the very core foundational

concepts around them.

It's a quick break and we'll write some more code in just a moment.