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

Java Arrays


You might be wondering what happens when we have a game with lots of variables or objects to keep track of. An obvious example is our current project. As another example what about the game with a high score table with the top 100 scores?

We could declare and initialize 100 separate objects/variables like this.

Bullet bullet1;
Bullet bullet2;
Bullet bullet3;
//96 more lines like the above
Bullet bullet100;

Or taking the high score table situation:

int topScore1;
int topScore2;
int topScore3;
//96 more lines like the above
int topScore100;

Straight away this can seem unwieldy but what about when someone gets a new top score? Considering just the high scores scenario it is obvious we have a problem. We must shift the scores in every variable down one place. A nightmare begins.

topScore100 = topScore99;
topScore99 = topScore98;
topScore98 = topScore97;
//96 more lines like the above
topScore1 = score;

There must be a better way. When we have a whole array of variables what we need is a...