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)

Simple array example mini-app

Let's make a simple working array example. You can get the completed code for this example in the downloadable code bundle. It's at Chapter 15/Simple Array Example/MainActivity.java.

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

First, we declare our array, allocate five spaces, and initialize values for each of the elements. Then we output each of the values to the logcat console. Add this code to the onCreate method just after the call to setContentView:

// Declaring an array
int[] ourArray;
// Allocate memory for a maximum size of 5 elements
ourArray = new int[5];
// Initialize ourArray with values
// The values are arbitrary, but they must be int
// The indexes are not arbitrary. 0 through 4 or crash!
ourArray[0] = 25;
ourArray[1] = 50;
ourArray[2] = 125;
ourArray[3] = 68;
ourArray[4] = 47;
//Output all the stored values
Log.i("info", "Here is ourArray:");
Log.i("info...