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)

Errors, warnings, and bugs

The most common getting started errors are the syntax errors. They most frequently occur when we mistype a Java keyword or forget to leave a space after a keyword.

The following error occurs if you forget to leave a semicolon at the end of a line of code:

Figure 3.6 – Error due to a semicolon

Important note

There are occasions when we don't need semicolons. We will see these as we proceed.

Look at the following screenshot, which shows the error we get when we type in a word that the compiler doesn't recognize:

Figure 3.7 – Error that's shown when the compiler is unable to recognize a word

Also, notice that Android Studio is giving us a warning that we have some unused variables – warnings such as Field 'horizontalTouched' is never used. You can see these warnings if you hover the mouse pointer over the little yellow lines on the right of the editor window...