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Top 97 TypeScript Interview Questions & Answers (2026)

97 Questions 42 Beginner 33 Intermediate 22 Advanced

About TypeScript

TypeScript is Microsoft's open-source superset of JavaScript that adds static typing, catching errors at compile time rather than runtime. It has become the standard in large-scale frontend and Node.js development, adopted by Microsoft, Slack, Airbnb, and most major companies building substantial codebases. The 2024 State of JS survey shows TypeScript usage has surpassed plain JavaScript in production projects.

What to Expect in a TypeScript Interview

TypeScript interviews test the type system deeply — interfaces vs type aliases, generics, utility types (Partial, Pick, Omit, Record), conditional types, mapped types, and template literal types. Practical questions cover tsconfig options, strict mode, and TypeScript integration with React, Node.js, and build tools.

How to Use This Guide

TypeScript knowledge is tested alongside JavaScript in most interviews. Many questions assume strong JavaScript fundamentals and probe TypeScript-specific additions. Build your JavaScript foundation first, then focus on the TypeScript type system — generics are the most commonly tested advanced topic.

Curated by Tech Baithak Editorial Team  ·  Last updated: May 2026

Beginner 42 questions

Core concepts every TypeScript developer must know.

01 What is TypeScript? 02 What are the main differences between TypeScript and JavaScript? 03 What are the basic types in TypeScript? 04 What is type annotation in TypeScript? 05 What is type inference in TypeScript? 06 What is the any type in TypeScript? 07 What is the unknown type and how does it differ from any? 08 What is an interface in TypeScript? 09 What is the difference between interface and type alias in TypeScript? 10 What are union types in TypeScript? 11 What are intersection types in TypeScript? 12 What are enums in TypeScript? 13 What is a tuple in TypeScript? 14 What is the void type in TypeScript? 15 What is the never type in TypeScript? 16 What is type narrowing in TypeScript? 17 What is a type guard in TypeScript? 18 What are optional properties and parameters in TypeScript? 19 What is the readonly modifier in TypeScript? 20 What is a type assertion in TypeScript? 21 What is the difference between as and angle bracket syntax for type assertions? 22 What is a class in TypeScript? 23 What are access modifiers in TypeScript? 24 What is abstract class in TypeScript? 25 What is the difference between extends and implements in TypeScript? 26 What is the tsconfig.json file? 27 What does strict mode do in TypeScript? 28 What is a function overload in TypeScript? 29 What are default parameter values in TypeScript? 30 What is the keyof operator in TypeScript? 31 What is typeof operator in TypeScript? 32 What is the difference between type and interface in TypeScript? 33 What are literal types in TypeScript? 34 What is as const in TypeScript? 35 What is optional chaining in TypeScript? 36 What is nullish coalescing in TypeScript? 37 What are generics in TypeScript? 38 What are generic constraints in TypeScript? 39 What are TypeScript utility types? 40 What is the difference between Partial and Required utility types? 41 What are modules in TypeScript? 42 What is declaration merging in TypeScript?
Intermediate 33 questions

Practical knowledge for developers with hands-on experience.

01 What are mapped types in TypeScript? 02 What are conditional types in TypeScript? 03 What is the infer keyword in TypeScript? 04 What are template literal types in TypeScript? 05 What are decorators in TypeScript? 06 What is the ReturnType utility type? 07 What is the Parameters utility type? 08 What is the Record utility type? 09 What is the Pick utility type? 10 What is the Omit utility type? 11 What are index signatures in TypeScript? 12 What is the Exclude utility type? 13 What is the Extract utility type? 14 What is the NonNullable utility type? 15 What is a namespace in TypeScript? 16 What are ambient declarations in TypeScript? 17 What is a declaration file (.d.ts) in TypeScript? 18 What is the difference between import type and import in TypeScript? 19 What is the satisfies operator in TypeScript? 20 What are discriminated unions in TypeScript? 21 What are generic default types in TypeScript? 22 What is module augmentation in TypeScript? 23 What is the InstanceType utility type? 24 What is the Awaited utility type in TypeScript? 25 What is covariance and contravariance in TypeScript? 26 What is a type predicate in TypeScript? 27 What is the difference between type widening and type narrowing? 28 What is the this type in TypeScript? 29 What is strict null checks and why is it important? 30 What is the useUnknownInCatchVariables option in TypeScript? 31 What are recursive types in TypeScript? 32 What is the Extract and Exclude difference and when to use each? 33 What are higher-order types in TypeScript?
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