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

A random diversion


Sometimes in our apps, we will want a random number and Java provides us with the Random class for these occasions. There are many possible uses for this class; perhaps our app wants to show a random tip-of-the-day or a game that has to choose between scenarios, or a quiz that asks random questions.

The Random class is part of the Java API and is fully compatible in our Android apps.

Let's have a look at how we can create random numbers, and later in the chapter we will put it to practical use. All the hard work is done for us by the Random class. First, we need to create an object of type Random.

Random randGenerator = new Random();

Then we use our new object's nextInt method to generate a random number between a certain range.

This line of code generates the random number using our Random object and stores the result in the ourRandomNumber variable:

int ourRandomNumber = randGenerator.nextInt(10);

The number that we enter for the range starts from zero. So the preceding...