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

Chapter 15. Arrays, ArrayList, Map and Random Numbers

In this chapter, we will learn about Java arrays that allow us to manipulate a potentially huge amount of data in an organized and efficient manner. We will also use a close Java relation to arrays, the ArrayList, and see the differences between them.

In addition, we will see how to handle data which can be logically linked to an identifier as part of a pair using a Map and we will also build some mini apps to practice these new concepts.

Furthermore we will see how to generate random numbers.

The topics we will cover in this chapter include the following:

  • The Random class

  • Handling data with arrays

  • Arrays mini app

  • Dynamic arrays, including mini app

  • Multi-dimensional arrays, including mini app

  • The ArrayList class

  • The enhanced for loop

  • Java HashMap

But first, let's learn about the Random class.