Book Image

Android Programming for Beginners - Second Edition

By : John Horton
Book Image

Android Programming for Beginners - Second Edition

By: John Horton

Overview of this book

Are you trying to start a career in programming, but haven't found the right way in? Do you have a great idea for an app, but don't know how to make it a reality? Or maybe you're just frustrated that in order to learn Android, you must know Java. If so, then this book is for you. This new and expanded second edition of Android Programming for Beginners will be your companion to create Android Pie applications from scratch. We will introduce you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. All examples use the up-to-date API classes, and are created from within Android Studio, the official Android development environment that helps supercharge your application development process. After this crash course, we'll dive deeper into Android programming and you'll learn how to create applications with a professional-standard UI through fragments and store your user's data with SQLite. In addition, you'll see how to make your apps multilingual, draw to the screen with a finger, and work with graphics, sound, and animations too. By the end of this book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (35 chapters)
Android Programming for Beginners - Second Edition
Contributors
Preface
Other Books You May Enjoy
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 app uses variables that 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 enum keyword, 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 all in uppercase:

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

Note at this point that 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...