Guides / typescript

typescript Guides

13 guides

beginner

TypeScript Basic Types

Annotate primitives, arrays, tuples, and any with TypeScript types

TypeScript Enums

Named constants with numeric or string enum members

TypeScript Interfaces

Define object shapes, optional properties, and extendable contracts

intermediate

Advanced TypeScript Generics

Constraints, defaults, inference, and variance patterns for reusable generic APIs

TypeScript Generics

Write reusable functions and types that work across type parameters

TypeScript Type Guards

Narrow types with typeof, instanceof, in, and custom predicates

TypeScript Type Narrowing

How control flow analysis refines union types down to a single member

TypeScript Unions

Combine types with union, intersection, and discriminated unions

TypeScript Utility Types

Transform types with Partial, Pick, Omit, Record, and ReturnType

advanced

TypeScript Conditional Types

Branch on type relationships with extends, infer, and distribution

TypeScript Declaration Files

Author .d.ts files to describe types for JavaScript and ambient modules

TypeScript Decorators

Annotate and extend classes, methods, and fields with reusable decorators

TypeScript Mapped Types

Transform every property of a type with key remapping and modifiers