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

A random diversion


Sometimes, we will want a random number in our apps and, for these occasions, Kotlin provides us with the Random class. There are many possible uses for this class, such as if 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 Android API and is fully compatible in our Android apps.

Let's take a look at how to create random numbers. All the hard work is done for us by the Random class. First, we need to create a Random object, as follows:

val randGenerator = Random()

Then, we use our new object's nextInt function to generate a random number between a certain range. The following line of code generates the random number using our randGenerator object and stores the result in the ourRandomNumber variable:

var ourRandomNumber = randGenerator.nextInt(10)

The number that we enter for the range starts from zero. So, the preceding line will generate a random number between...