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

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, which 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 multi-dimensional arrays can be useful.

Multidimensional Array mini app

Let's make a simple multi-dimensional array example. You can get the working project for this example in the download bundle. It can be found in the Chapter 15/Multidimensional Array Example/MainActivity.java folder.

Create a project with an empty Activity and call it Multidimensional Array Example.

After the call to setContentView in onCreate, declare and initialize a two-dimensional array as follows:

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

// declare and allocate in separate...