Book Image

Learning Java by Building Android Games - Second Edition

By : John Horton
Book Image

Learning Java by Building Android Games - Second Edition

By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems presently. It uses the most popular programming language, Java, as the primary language for building apps of all types. However, this book is unlike other Android books in that it doesn’t assume that you already have Java proficiency. This new and expanded second edition of Learning Java by Building Android Games shows you how to start building Android games from scratch. The difficulty level will grow steadily as you explore key Java topics, such as variables, loops, methods, object oriented programming, and design patterns, including code and examples that are written for Java 9 and Android P. At each stage, you will put what you’ve learned into practice by developing a game. You will build games such as Minesweeper, Retro Pong, Bullet Hell, and Classic Snake and Scrolling Shooter games. In the later chapters, you will create a time-trial, open-world platform game. By the end of the book, you will not only have grasped Java and Android but will also have developed six cool games for the Android platform.
Table of Contents (30 chapters)
Learning Java by Building Android Games Second Edition
Contributors
Preface
Index

Enumerations


An enumeration is a list of all the possible values in a logical collection. Java enum is a great way of, well, enumerating things. For example, if our game uses variables which can only be in a specific range of values and if those values could logically form a collection or a set, then enumerations are probably appropriate to use. They will make your code clearer and less error-prone.

To declare an enum in Java we use the keyword, enum, followed by the name of the enumeration, followed by the values the enumeration can have, enclosed in a pair of curly braces {...}.

As an example, examine this enumeration declaration. Note that it is a convention to declare the values from the enumeration in all uppercase.

private enum zombieTypes {
   REGULAR, RUNNER, CRAWLER, SPITTER, BLOATER, SNEAKER 
};

Note at this point we have not declared any instances of zombieTypes, just the type itself. If that sounds odd, think about it like this. We created the Apple class, but to use it, we had to...