TypeScript interview questions
Review short answers, detailed answers, practical code and common mistakes.
1. How would you explain TypeScript Introduction in TypeScript during an interview?beginner
TypeScript Introduction is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem typescript introduction solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
interface Order {
id: number;
total: number;
status: "paid" | "pending";
customer: string;
}
const order: Order = { id: 42, total: 50, status: "paid", customer: "Asha" };
console.log(order);2. How would you explain TypeScript Setup in TypeScript during an interview?beginner
TypeScript Setup is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem typescript setup solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
3. How would you explain Basic Types in TypeScript during an interview?beginner
Basic Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem basic types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
4. How would you explain Arrays and Tuples in TypeScript during an interview?beginner
Arrays and Tuples is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem arrays and tuples solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "Arrays and Tuples";
const duration: number = 53;
console.log(`Learning ${lesson} in ${duration} minutes.`);5. How would you explain Enums in TypeScript during an interview?beginner
Enums is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem enums solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
6. How would you explain Interfaces in TypeScript during an interview?beginner
Interfaces is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem interfaces solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
7. How would you explain Type Aliases in TypeScript during an interview?beginner
Type Aliases is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem type aliases solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
interface Order {
id: number;
total: number;
status: "paid" | "pending";
customer: string;
}
const order: Order = { id: 42, total: 56, status: "paid", customer: "Asha" };
console.log(order);8. How would you explain Union and Intersection Types in TypeScript during an interview?beginner
Union and Intersection Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem union and intersection types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
9. How would you explain Functions in TS in TypeScript during an interview?beginner
Functions in TS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem functions in ts solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
10. How would you explain Classes in TS in TypeScript during an interview?beginner
Classes in TS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem classes in ts solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "Classes in TS";
const duration: number = 59;
console.log(`Learning ${lesson} in ${duration} minutes.`);11. How would you explain Generics Basics in TypeScript during an interview?intermediate
Generics Basics is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem generics basics solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
12. How would you explain Generics Advanced in TypeScript during an interview?intermediate
Generics Advanced is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem generics advanced solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
13. How would you explain Utility Types in TypeScript during an interview?intermediate
Utility Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem utility types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
interface Order {
id: number;
total: number;
status: "paid" | "pending";
customer: string;
}
const order: Order = { id: 42, total: 62, status: "paid", customer: "Asha" };
console.log(order);14. How would you explain Type Assertion in TypeScript during an interview?intermediate
Type Assertion is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem type assertion solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
15. How would you explain Type Guards in TypeScript during an interview?intermediate
Type Guards is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem type guards solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
16. How would you explain Modules in TypeScript during an interview?intermediate
Modules is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem modules solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "Modules";
const duration: number = 65;
console.log(`Learning ${lesson} in ${duration} minutes.`);17. How would you explain Decorators in TypeScript during an interview?intermediate
Decorators is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem decorators solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
18. How would you explain TS with React in TypeScript during an interview?intermediate
TS with React is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem ts with react solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
19. How would you explain TS with NodeJS in TypeScript during an interview?intermediate
TS with NodeJS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem ts with nodejs solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "TS with NodeJS";
const duration: number = 68;
console.log(`Learning ${lesson} in ${duration} minutes.`);20. How would you explain Compiler Config in TypeScript during an interview?intermediate
Compiler Config is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem compiler config solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
21. How would you explain Strict Mode in TypeScript during an interview?advanced
Strict Mode is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem strict mode solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
22. How would you explain Strict Null Checks in TypeScript during an interview?advanced
Strict Null Checks is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem strict null checks solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "Strict Null Checks";
const duration: number = 71;
console.log(`Learning ${lesson} in ${duration} minutes.`);23. How would you explain Index Signatures in TypeScript during an interview?advanced
Index Signatures is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem index signatures solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
24. How would you explain Mapped Types in TypeScript during an interview?advanced
Mapped Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem mapped types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
25. How would you explain Conditional Types in TypeScript during an interview?advanced
Conditional Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem conditional types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
interface Order {
id: number;
total: number;
status: "paid" | "pending";
customer: string;
}
const order: Order = { id: 42, total: 74, status: "paid", customer: "Asha" };
console.log(order);26. How would you explain Template Literal Types in TypeScript during an interview?advanced
Template Literal Types is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem template literal types solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
27. How would you explain Declaration Files in TypeScript during an interview?advanced
Declaration Files is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem declaration files solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
28. How would you explain Webpack and TS in TypeScript during an interview?advanced
Webpack and TS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem webpack and ts solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
const lesson: string = "Webpack and TS";
const duration: number = 77;
console.log(`Learning ${lesson} in ${duration} minutes.`);29. How would you explain TS Best Practices in TypeScript during an interview?advanced
TS Best Practices is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem ts best practices solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
30. How would you explain TypeScript Review in TypeScript during an interview?advanced
TypeScript Review is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem typescript review solves in TypeScript. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.