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

More polymorphism


We already know that polymorphism means many forms, but what does it mean to us?

Boiled down to its simplest, it means the following:

Note

Any subclass can be used as part of code that uses the super class.

This means that we can write code that is easier to understand, and simpler to change.

Also, we can write code for the super class and rely on the fact that no matter how many times it is subclassed, the code will still work within certain parameters. Let's discuss an example.

Suppose that we want to use polymorphism to help write a zoo management app. We will probably want to have a function, such as feed. Let's also say we have Lion, Tiger, and Camel classes, which all inherit from a parent class called Animal. We will also probably want to pass a reference to the animal to be fed into the feed function. This might seem like we need to write a feed function for each and every type of Animal.

Instead, however, we can write polymorphic functions with polymorphic arguments...