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 Kot- lin. In chapters 2-4, you’ll learn how the most basic Java programming con- cepts—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 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 effectively solve some of the most com- mon programming tasks, such as working with collections. Finally, in chapter 6, you’ll become familiar with one of the key Kotlin specialties: its support for deal- ing with null values.