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

Standard library functions

Kotlin provides a standard library that is meant to augment, not replace, the standard Java library. There are many functions that adapt Java types and methods and allow them to be used as idiomatic Kotlin. In this section, we will cover some of the lower-level functions that have far reaching use.

Apply

Apply is a Kotlin standard library extension function declared on Any, so it could be invoked on instances of all types. Apply accepts a lambda that is invoked with the receiver being the instance that apply was called on. Apply then returns the original instance.

It's primary use is to make the code that needs to initialize an instance more readable by allowing functions and properties to be...