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)

Method structure

The first part of a method that we write is called the signature. Here is a hypothetical method signature:

public boolean addContact(boolean isFriend, string name)

If we add an opening and closing pair of curly braces, {}, with some code that the method performs, then we have a complete method – a definition. Here is another made up yet syntactically correct method:

private void setCoordinates(int x, int y){
   // code to set coordinates goes here
}

As we have seen, we could then use our new method from another part of our code like this:

// I like it here
setCoordinates(4,6);// now I am going off to setCoordinates method
// Phew, I'm back again - code continues here

At the point where we call the setCoordinates method, our program's execution would branch to the code contained within that method. The method would execute all the statements inside it, step by step, until it reaches the end, and then return control to...