Introducing OOP

In Chapter 1, Getting Started with Android and Kotlin, we mentioned that Kotlin was an object-oriented language. An object-oriented language requires us to use OOP; it isn't an optional extra, it's part of Kotlin.

Let's find out a little bit more.

What is OOP exactly?

OOP is a way of programming that involves breaking our requirements down into chunks that are more manageable than the whole.

Each chunk is self-contained, and potentially reusable, by other programs, while working together as a whole with the other chunks.

These chunks are what we have been referring to as objects. When we plan/code an object, we do so with a class. A class can be thought of as the blueprint of an object.

We implement an object of a class. This is called an instance of a class. Think about a house blueprint – you can't live in it, but you can build a house from it; so, you build an instance of it. Often, when we design classes for our apps, we write them to represent real-world things.

However, OOP...