Book Image

Learn Kotlin Programming - Second Edition

By : Stephen Samuel, Stefan Bocutiu
Book Image

Learn Kotlin Programming - Second Edition

By: Stephen Samuel, Stefan Bocutiu

Overview of this book

Kotlin is a general-purpose programming language used for developing cross-platform applications. Complete with a comprehensive introduction and projects covering the full set of Kotlin programming features, this book will take you through the fundamentals of Kotlin and get you up to speed in no time. Learn Kotlin Programming covers the installation, tools, and how to write basic programs in Kotlin. You'll learn how to implement object-oriented programming in Kotlin and easily reuse your program or parts of it. The book explains DSL construction, serialization, null safety aspects, and type parameterization to help you build robust apps. You'll learn how to destructure expressions and write your own. You'll then get to grips with building scalable apps by exploring advanced topics such as testing, concurrency, microservices, coroutines, and Kotlin DSL builders. Furthermore, you'll be introduced to the kotlinx.serialization framework, which is used to persist objects in JSON, Protobuf, and other formats. By the end of this book, you'll be well versed with all the new features in Kotlin and will be able to build robust applications skillfully.
Table of Contents (21 chapters)
Free Chapter
1
Section 1: Fundamental Concepts in Kotlin
5
Section 2: Practical Concepts in Kotlin
15
Section 3: Advanced Concepts in Kotlin

Classes

Classes are the main building blocks of any object-oriented programming language. The concept of a class was first studied by Aristotle. He was the first one to come up with the concept of a class of fishes and a class of birds. All objects, despite being unique, are part of a class and share a common behavior.

A class enables you to create your own type by grouping together methods and variable of other types. Think of a class as a blueprint; it describes the data and the behavior of a type.

Classes are declared by using the class keyword, as shown in the following example:

    class Deposit { 
    } 

Compared to Java, you can define multiple classes within the same source file. The class keyword can be preceded by the access level. If it is not specified, it will default to public; this means anyone can create objects of this class. The name of the class follows the...