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

Entering the nth dimension with Arrays


We very briefly mentioned that an array can even hold other arrays at each position. And of course, if an array holds lots of arrays that in turn hold lots of some other type; how do we access the values in the contained arrays? And why would we ever need this anyway? Look at this next example of where multidimensional arrays can be useful.

Multidimensional Array mini app

Let's make a simple multidimensional array example. You can get the working project for this example in the download bundle. It is in the Chapter 12/Multidimensional Array Example/MainActivity.java.

Create a project with an empty Activity and call it Multidimensional Array Example. Leave the Activity name at the default it is not important.

After the call to super.onCreate… in onCreate, declare and initialize a two-dimensional array like this:

// Random object for generating question numbers
Random randInt = new Random();
// a variable to hold the random value generated
int questionNumber...