TypeScript Interview: 200 Questions and Answers

The book "TypeScript Interview: 200 Questions and Answers" is a comprehensive training simulator for preparing for a technical interview on TypeScript. The author has collected and structured the most common and complex questions asked at interviews in Russian and international IT companies. Each question is accompanied by a detailed answer, code examples, and explanations.

What is this book about?

The book covers all key TypeScript topics:

• Basic and advanced types (union, intersection, literal, mapped, conditional)
• Generics and their practical application
• Decorators, mixins, utility types (Partial, Required, Pick, Omit, etc.)
• Modules, namespaces, dependency resolution
• Type compatibility, type inference, type guards
• Working with DOM, async/await, Promise, fetch
• Integrating TypeScript with React, Node.js, Express
• Configuring tsconfig, strict modes, best practices
• Real-world cases: API typing, working with forms, Redux, GraphQL

Who is this book for?

• Junior developers — systematize knowledge, fill gaps, learn typical interview questions
• Middle developers — deepen understanding of complex topics, prepare for tricky questions
• Team Leads and HR — can use it as a base for creating their own questions

What will the reader learn?

• How to properly type functions, objects, classes, and promises
• How interface differs from type and when to use which
• How conditional and mapped types work
• How to avoid errors with any, unknown, never
• How to type complex data structures (trees, graphs, recursive types)
• How to set up strict typing in a project
• How to answer questions about TypeScript performance

Book structure

200 questions are divided into thematic sections. At the end of each chapter, there are self-test tasks and links to documentation. The book is suitable both for sequential reading and for selectively searching for answers before a specific interview.

This is not a reference guide, but a practical manual that will help you feel confident in an interview and get an offer from your dream company.