Overview
TypeScript is a strongly typed programming language that builds on JavaScript by adding optional static types. Developed and maintained by Microsoft, it compiles to standard JavaScript and can run anywhere JavaScript runs: browsers, Node.js, Deno, Bun, and beyond.
TypeScript’s type system catches a wide class of bugs at compile time rather than at runtime, making codebases easier to refactor, document, and navigate with IDE tooling.
Topics in This Section
TypeScript
Core language documentation: type annotations, interfaces, generics, enums, utility types, and the TypeScript compiler (tsc). Covers the key differences from JavaScript and how TypeScript integrates with build tools.
TypeScript Libraries
Notable libraries and utilities that are either TypeScript-native or have first-class TypeScript support.
Key Concepts
- Type Annotations: Explicitly declare the type of variables, function parameters, and return values
- Interfaces and Types: Structural typing with named shapes for objects and function signatures
- Generics: Write code that works with any type while preserving type information
- Type Inference: TypeScript often infers types without explicit annotations
- Strict Mode: Enables the full power of TypeScript’s type checker for maximum safety
- Declaration Files (
.d.ts): Type definitions for JavaScript libraries without TypeScript source