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)

ArrayList

ArrayList is like a regular Java array on steroids. It overcomes some of the shortfalls of arrays, such as having to predetermine the size. It adds some useful methods to make its data easy to manage and it uses an enhanced version of a for loop that is clearer to use than a regular for loop.

Let's look at some code that uses an ArrayList instance:

// Declare a new ArrayList called myList to hold int variables
ArrayList<int> myList;
 
// Initialize the myList ready for use
myList = new ArrayList<int>();

In the previous code, we declared and initialized a new ArrayList called myList. We can also do this in a single step like this code shows:

ArrayList<int> myList = new ArrayList<int>();

Nothing especially interesting so far, so let's take a look at what we can actually do with ArrayList. Let's use a String ArrayList instance this time:

// declare and initialize a new ArrayList
ArrayList<String> myList = new ArrayList...