Learn TypeScript

Set up TypeScript, compile your first program, and learn the basic types, inference, arrays, functions and objects.

• Introduction to TypeScript
• Installing and Running TypeScript
• Your First Program
• Basic Types and Annotations
• Type Inference
• Arrays and Tuples
• any, unknown and never
• Typing Functions
• Object Types

Name and combine types with aliases, interfaces, unions and intersections, and narrow them safely.

• Type Aliases
• Interfaces
• Union Types
• Literal Types
• Narrowing
• Discriminated Unions
• Intersection Types
• Enums
• null and undefined
• Index Signatures and Record

Type callbacks and overloads, and use classes with access modifiers, abstract classes and interfaces.

• Function Types and Overloads
• Classes
• Abstract Classes and implements

Write reusable, type-safe functions, interfaces and classes with generics and constraints.

• Generics
• Generic Constraints and Defaults

Derive new types from existing ones with keyof, utility types, mapped, conditional and template literal types.

• keyof, typeof and Indexed Access
• Utility Types
• Mapped Types
• Conditional Types and infer
• Template Literal Types
• Type Guards and Assertion Functions
• as, as const, satisfies and !

Modules and declaration files, tsconfig options, typing the DOM, and typing async code and API data.

• Modules and Imports
• Declaration Files and @types
• tsconfig.json and Strict Mode
• TypeScript with the DOM
• Async Code and API Data

Questions asked in front-end, full-stack and Node.js interviews, with clear answers.

• Beginner Questions
• Intermediate Questions
• Advanced Questions