Book Image

Learning Java by Building Android Games - Third Edition

By : John Horton
5 (1)
Book Image

Learning Java by Building Android Games - Third Edition

5 (1)
By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems today. It uses the most popular programming language, Java, as one of the primary languages for building apps of all types. Unlike most other Android books, this book doesn’t assume that you have any prior knowledge of Java programming, instead helps you get started with building Android games as a beginner. This new, improved, and updated third edition of Learning Java by Building Android Games helps you to build Android games from scratch. Once you've got to grips with the fundamentals, the difficulty level increases steadily as you explore key Java topics, such as variables, loops, methods, object-oriented programming (OOP), and design patterns while working with up-to-date code and supporting examples. At each stage, you'll be able to test your understanding by implementing the concepts that you’ve learned to develop a game. Toward the end, you’ll build games such as Sub Hunter, Retro Pong, Bullet Hell, Classic Snake, and Scrolling Shooter. By the end of this Java book, you'll not only have a solid understanding of Java and Android basics but will also have developed five cool games for the Android platform.
Table of Contents (24 chapters)

OOP and inheritance

We have seen how we can use other people's hard work by instantiating/creating objects from the classes of an API such as Android. But this whole OOP thing goes even further than that.

What if there is a class that has loads of useful functionality in it but not quite what we want? We can inherit from the class and then further refine or add to how it works and what it does.

You might be surprised to hear that we have done this already. In fact, we have done this with every single app we have created. I mentioned this near the start of the chapter. When we use the extends keyword we are inheriting from another class. Here is the code from the previous mini-app:

public class MainActivity extends...

Here, we are inheriting the Activity class along with all its functionality—or more specifically, all the functionality that the class designers want us to have access to. Here are some of the things we can do to classes we have extended.

We...