Book Image

Android Programming with Kotlin for Beginners

By : John Horton
5 (1)
Book Image

Android Programming with Kotlin for Beginners

5 (1)
By: John Horton

Overview of this book

Android is the most popular mobile operating system in the world and Kotlin has been declared by Google as a first-class programming language to build Android apps. With the imminent arrival of the most anticipated Android update, Android 10 (Q), this book gets you started building apps compatible with the latest version of Android. It adopts a project-style approach, where we focus on teaching the fundamentals of Android app development and the essentials of Kotlin by building three real-world apps and more than a dozen mini-apps. The book begins by giving you a strong grasp of how Kotlin and Android work together before gradually moving onto exploring the various Android APIs for building stunning apps for Android with ease. You will learn to make your apps more presentable using different layouts. You will dive deep into Kotlin programming concepts such as variables, functions, data structures, Object-Oriented code, and how to connect your Kotlin code to the UI. You will learn to add multilingual text so that your app is accessible to millions of more potential users. You will learn how animation, graphics, and sound effects work and are implemented in your Android app. By the end of the book, you will have sound knowledge about significant Kotlin programming concepts and start building your own fully featured Android apps.
Table of Contents (33 chapters)
Android Programming with Kotlin for Beginners
Contributors
Preface
Index

Leaving comments in our Kotlin code


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

// This is a comment and it could be useful

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

// The code below used to send a message
// Log.i("info","our message here")
// But now it doesn't do anything
// And I am getting ahead of where I should be

Note

Using comments to comment out code should only be a temporary measure. Once you have found the correct code to use, commented-out code should be cut to keep the code file clean and organized.

Let's take a look at two separate ways to send messages in Android, and then we can write...