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

ArrayLists


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

Let's look at some code that uses ArrayList:

// 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, as demonstrated by the following code:

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 this time:

// declare and initialize a new ArrayList
ArrayList<String> myList = new ArrayList<String>();

// Add a...