TypeScript Exam Study Guide
Seven topic guides covering everything tested on TypeScript interviews and exams. Code examples, exam traps, and tips throughout.
Test your TypeScript knowledge →Free · No sign-upTypeScript Types vs Interfaces — When to Use Which
Types and interfaces are the foundation of TypeScript. Here's what exams test — the differences and when each applies.
TypeScript Type Inference Explained — When to Add Type Annotations
TypeScript infers most types automatically. Here's when you need annotations and when they just add noise.
TypeScript Union & Intersection Types — Discriminated Unions Explained
Union and intersection types model "or" and "and" relationships. Discriminated unions are the most powerful pattern.
TypeScript Generics Explained — Generic Functions, Constraints & keyof
Generics enable reusable, type-safe code. Here's what interviews test — from basic generic functions to constraints.
TypeScript Utility Types — Partial, Required, Pick, Omit, Record
Utility types transform existing types into new ones. These save you from writing repetitive type definitions.
TypeScript Type Narrowing — typeof, instanceof, Custom Type Guards
TypeScript narrows union types inside conditional blocks. Here's all the narrowing patterns and custom type guards.
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