Kotlin by Example

Introduction

The book "Kotlin by Example", released by the JetBrains team in 2020, is a compact (200 pages) practical guide to the Kotlin programming language. Unlike many academic textbooks, this book is built around specific code examples, allowing the reader to immediately dive into real-world tasks and see how Kotlin works in practice. The title fully reflects the essence: you learn by analyzing and modifying ready-made programs.

What the book is about

The book covers all key features of Kotlin, starting from basic syntax and ending with advanced topics such as coroutines and DSL. Each chapter contains several complete examples with explanations. Main sections:

• Language basics: variables, functions, control structures, working with null.
• Object-oriented programming: classes, interfaces, inheritance, data classes.
• Functional programming: lambdas, higher-order functions, collections.
• Extensions and delegates: mechanisms that make Kotlin flexible.
• Coroutines: asynchronous programming and concurrency.
• DSL and builders: creating domain-specific languages.

Who this book is for

The book is aimed at programmers already familiar with the basics of at least one language (Java, Python, C#). It is not suitable for absolute beginners, as it does not explain basic programming concepts (loops, conditions, data types) from scratch. However, if you already know how to write code and want to quickly switch to Kotlin, this is an ideal option.

What the reader will learn

• How to write concise and safe code in Kotlin.
• How to use null safety to prevent errors.
• How to apply functional constructs (map, filter, reduce).
• How to create extensions for existing classes.
• How to work with coroutines for asynchronous operations.
• How to build DSLs for configuration and testing.
• How to integrate Kotlin with Java (interoperability).

Strengths

The main advantage of the book is its practical focus. Each example can be immediately run and experimented with. The code is well-commented, and the explanations are concise and to the point. The book is not overloaded with theory, which speeds up learning. It is also worth noting that the authors are developers of the Kotlin language itself, so the material is accurate and up-to-date.

Who it is recommended for

The book is worth reading for:

• Java developers looking to switch to Kotlin.
• Students learning modern programming languages.
• Anyone who wants to quickly master Kotlin through practice.

If you prefer to learn from real-world tasks rather than abstract examples, "Kotlin by Example" will be an excellent choice.