The goal of this part of the book is to get you productive writing Kotlin code that uses existing APIs. Chapter 1 will introduce you to the general traits of Kotlin.
In chapters 2-4, you’ll learn how basic programming concepts—statements, functions, classes, and types—map to Kotlin code and how Kotlin enriches them to make programming more pleasant. You’ll be able to rely on your existing knowledge of other object-oriented languages, like Java, as well as tools, such as IDE coding-assistance features and the Java-to-Kotlin converter, to get up to speed quickly. In chapter 5, you’ll find out how lambdas help you avoid repetition and effectively solve common programming tasks. Chapter 6 teaches you how Kotlin allows you to elegantly modify collections using a functional programming approach. In chapter 7, you’ll become familiar with one of the key Kotlin specialties: its support for dealing with null values. In chapter 8, you’ll take a closer look at the basics of Kotlin’s type system, from basic numbers to the special Any and Nothing types. You’ll also learn more about collection types, including their read-only and mutable versions, and get introduced to arrays.