Kotlin in Action

Kotlin in Action

Kotlin in Action guides experienced Java developers from the language basics of Kotlin all the way through building applications to run on the JVM and Android devices. Foreword by Andrey Breslav, Lead Designer of Kotlin.

Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications.

About the Technology

Developers want to get work done - and the less hassle, the better. Coding with Kotlin means less hassle. The Kotlin programming language offers an expressive syntax, a strong intuitive type system, and great tooling support along with seamless interoperability with existing Java code, libraries, and frameworks. Kotlin can be compiled to Java bytecode, so you can use it everywhere Java is used, including Android. And with an effi cient compiler and a small standard library, Kotlin imposes virtually no runtime overhead.

About the Book

Kotlin in Action teaches you to use the Kotlin language for production-quality applications. Written for experienced Java developers, this example-rich book goes further than most language books, covering interesting topics like building DSLs with natural language syntax. The authors are core Kotlin developers, so you can trust that even the gnarly details are dead accurate.

What's Inside

• Functional programming on the JVM
• Writing clean and idiomatic code
• Combining Kotlin and Java
• Domain-specific languages

About the Reader

This book is for experienced Java developers.

About the Author

Dmitry Jemerov and Svetlana Isakova are core Kotlin developers at JetBrains.

Table of Contents

PART 1 - INTRODUCING KOTLIN

• Kotlin: what and why
• Kotlin basics
• Defining and calling functions
• Classes, objects, and interfaces
• Programming with lambdas
• The Kotlin type system

PART 2 - EMBRACING KOTLIN

• Operator overloading and other conventions
• Higher-order functions: lambdas as parameters and return values
• Generics
• Annotations and reflection
• DSL construction

Programming Kotlin

Familiarize yourself with all of Kotlin's features with this in-depth guide

Programming Kotlin
About This Book

• Get a thorough introduction to Kotlin
• Learn to use Java code alongside Kotlin without any hiccups
• Get a complete overview of null safety, Generics, and many more interesting features

Who This Book Is For
The book is for existing Java developers who want to learn more about an alternative JVM language. If you want to see what Kotlin has to offer, this book is ideal for you.

What You Will Learn

• Use new features to write structured and readable object-oriented code
• Find out how to use lambdas and higher order functions to write clean, reusable, and simple code
• Write unit tests and integrate Kotlin tests with Java code in a transitioning code base
• Write real-world production code in Kotlin in the style of microservices
• Leverage Kotlin's extensions to the Java collections library
• Use destructuring expressions and find out how to write your own
• Write code that avoids null pointer errors and see how Java-nullable code can integrate with features in a Kotlin codebase
• Discover how to write functions in Kotlin, see the new features available, and extend existing libraries
• Learn to write an algebraic data types and figure out when they should be used

In Detail
Kotlin has been making waves ever since it was open sourced by JetBrains in 2011; it has been praised by developers across the world and is already being adopted by companies. This book provides a detailed introduction to Kotlin that shows you all its features and will enable you to write Kotlin code to production.

We start with the basics: get you familiar with running Kotlin code, setting up, tools, and instructions that you can use to write basic programs. Next, we cover object oriented code: functions, lambdas, and properties - all while using Kotlin's new features.

Then, we move on to null safety aspects and type parameterization. We show you how to destructure expressions and even write your own. We also take you through important topics like testing, concurrency, microservices, and a whole lot more. By the end of this book you will be able to compose different services and build your own applications.

Style and approach
An easy to follow guide that covers the full set of features in Kotlin programming.

Kotlin for Android Developers: Learn Kotlin the easy way while developing an Android App

Kotlin for Android Developers: Learn Kotlin the easy way while developing an Android App

Are you tired of using an ancient, inexpressive and unsafe language to develop your Android apps? Do you cry out loud every time you see a Null Pointer Exception in your bug tracker? Then Kotlin is your solution! A language specifically created for Java developers, easy to learn, expressive, null safe and really intuitive. Your productivity will boost and your apps will become more robust. Learn Kotlin the easy way by example and discover the tricks that will make coding easier. In this book, I'll be creating an Android app from ground using Kotlin as the main language. The idea is to learn the language by example, instead of following a typical structure. I'll be stopping to explain the most interesting concepts and ideas about Kotlin, comparing it with Java 7. This way, you can see what the differences are and which parts of the language will help you speed up your work. This book is not meant to be a language reference, but a tool for Android developers to learn Kotlin and be able to continue with their own projects by themselves. I'll be solving many of the typical problems we have to face in our daily lives by making use of the language expressiveness and some other really interesting tools and libraries. The book is very practical, so it is recommended to follow the examples and the code in front of a computer and try everything it's suggested. You could, however, take a first read to get a broad idea and then dive into practice.