Book Image

Android Programming for Beginners - Third Edition

By : John Horton
Book Image

Android Programming for Beginners - Third Edition

By: John Horton

Overview of this book

Do you want to make a career in programming but don’t know where to start? Do you have a great idea for an app but don't know how to make it a reality? Or are you worried that you’ll have to learn Java programming to become an Android developer? Look no further! This new and expanded third edition of Android Programming for Beginners will be your guide to creating Android applications from scratch. The book starts by introducing you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. You’ll learn with the help of examples that use up-to-date API classes and are created within Android Studio, the official Android development environment that helps supercharge your mobile application development process. After a crash course on the key programming concepts, you’ll explore Android programming and get to grips with creating applications with a professional-standard UI using fragments and storing user data with SQLite. This Android Java book also shows you how you can make your apps multilingual, draw on the screen with a finger, and work with graphics, sound, and animations. By the end of this Android programming book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (30 chapters)

Entering the nth dimension with arrays

We very briefly mentioned that an array can even hold other arrays at each position. But if an array holds lots of arrays that 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 Chapter 15/Multidimensional Array Example/MainActivity.java.

Create a project using the Empty Activity template and call it Multidimensional Array Example.

After the call to setContentView in onCreate, add the following code, including declaring and initializing a two-dimensional array (highlighted):

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