Kotlin Interview: 200 Questions and Answers

The book "Kotlin Interview: 200 Questions and Answers" is a comprehensive collection created specifically for developers preparing for a technical interview. Whether you are a Junior developer aiming for your first job or an experienced Middle/Senior specialist looking to refresh your knowledge, this guide will be your reliable assistant.

What is this book about?

The book is structured by thematic sections and covers all key aspects of the Kotlin language. Each question is accompanied by a detailed, structured answer with code examples. You will find:

• Syntax Basics: data types, functions, lambdas, null safety, extension functions.
• Object-Oriented Programming: classes, interfaces, sealed classes, data classes, delegation.
• Functional Programming: collections, sequences, scope functions (let, apply, run, with, also).
• Coroutines and Asynchrony: CoroutineScope, launch, async, Flow, Channel, StateFlow.
• Generics and Variance: in, out, reified, star projection.
• Advanced Topics: reflection, annotations, inline functions, DSL.
• Practical Tasks: algorithmic questions, architecture questions (MVVM, Clean Architecture).

Who is this book for?

The book is intended for:

• Developers preparing for an interview for an Android developer or backend developer position in Kotlin.
• Students and course graduates looking to systematize their knowledge.
• Experienced developers transitioning from Java to Kotlin.
• Team leads and technical interviewers looking for a ready-made set of questions for conducting interviews.

What will the reader learn?

By working through all 200 questions, the reader will be able to confidently answer interviewers' questions, understand the inner workings of Kotlin, and avoid common mistakes. You will learn to:

• Explain the difference between var and val, lateinit and lazy.
• Properly use coroutines and handle exceptions in asynchronous code.
• Design types using generics and variance.
• Write concise and safe code using scope functions.
• Solve typical problems often given in interviews.

Each section of the book can be studied either separately or sequentially. For convenience, questions are grouped by difficulty level: from beginner to expert. Code examples are written in the current version of Kotlin (1.9+).

This book is not just a list of questions, but a full-fledged educational material that will help you pass the interview with confidence and get your dream job.