Book Image

Android Programming for Beginners

By : John Horton, Paresh Mayani
Book Image

Android Programming for Beginners

By: John Horton, Paresh Mayani

Overview of this book

Android is the most popular OS in the world. There are millions of devices accessing tens of thousands of applications. It is many people's entry point into the world of technology; it is an operating system for everyone. Despite this, the entry-fee to actually make Android applications is usually a computer science degree, or five years’ worth of Java experience. Android Programming for Beginners will be your companion to create Android applications from scratch—whether you’re looking to start your programming career, make an application for work, be reintroduced to mobile development, or are just looking to program for fun. We will introduce you to all the fundamental concepts of programming in an Android context, from the Java basics to working with the Android API. All examples 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, make location-aware apps with Google Maps integration, and store your user’s data with SQLite. In addition, you’ll see how to make your apps multilingual, capture images from a device’s camera, 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 (37 chapters)
Android Programming for Beginners
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Meet Java


Take a look at the MyActivity.java tab. Here, we can see the code that we briefly discussed.

Before we write our own methods to correspond with the methods that our buttons are already wired up to call, let's take a look at Java comments. Java comments are really handy when we are learning to code, as well as for experienced developers too.

Java comments

In programming, it is always a good idea to write messages known as code comments and sprinkle them liberally among your code. This is to remind us what on earth we were thinking at the time we wrote the code. To do this, you simply need to append a double forward slash and then type your comment like this:

// This is a comment and it could be useful

In addition to this, we can use comments to comment out a line of code. Suppose we have a line of code that we temporarily want to disable, then we can do so by adding two forward slashes, like this:

// The code below used to send a message
// Log.i("info","our message here");
// But now...