TypeScript
Definition
TypeScript is a statically typed superset of Javascript
- License: Apache 2.0
- Runtime: Compiles to JavaScript; runs on any JS engine (V8, SpiderMonkey, JavaScriptCore)
- Creator: Anders Hejlsberg (also created C Sharp)
- First released: 2012
Language Features
- Static typing: Optional type annotations with type inference
- Interfaces: Structural typing for object shapes
- Generics: Type-safe reusable components
- Enums: Named constants (numeric and string-based)
- Decorators: Metadata and meta-programming (experimental/stable depending on version)
- Utility types: Partial, Pick, Omit, Record, etc.
- Type guards: typeof, instanceof, user-defined-type-guards
Major Versions
| Version |
Year |
Key Features |
| TypeScript 1.0 |
2014 |
First stable release, type annotations |
| TypeScript 1.5 |
2015 |
Modules, enum, target |
| TypeScript 2.0 |
2016 |
Union-types, intersection-types, literal-types |
| TypeScript 2.4 |
2017 |
string-literal-types |
| TypeScript 2.8 |
2018 |
string-literal-types, const-assertions |
| TypeScript 3.0 |
2018 |
tuple-types, declaration-files |
| TypeScript 3.7 |
2019 |
optional-chaining, nullish-coalescing |
| TypeScript 4.0 |
2020 |
type-narrowing, satisfies-operator |
| TypeScript 4.7 |
2022 |
satisfies-operator, const-type-parameters |
| TypeScript 5.0 |
2023 |
declaration-files, const-type-parameters |
| TypeScript 5.4 |
2024 |
path-mapping, isolated-modules |
| Tool |
Purpose |
| tsc |
TypeScript compiler |
| ts-node |
Run TypeScript directly |
| ESLint + typescript-eslint |
Linting |
| Prettier |
Code formatting |
| Jest / Vitest |
Testing |
Ecosystem
| Framework/Library |
Description |
| Angular |
Google’s full-stack framework (written in TypeScript) |
| NestJS |
Server-side framework inspired by Angular |
| React + TypeScript |
React with type-safe props and hooks |
| Vue 3 |
Composition API with TypeScript support |
| Svelte |
Compile-time framework with TS support |
Use Cases
- Large-scale web applications (type safety at scale)
- Enterprise applications (Angular, NestJS)
- Library development (published to npm with types)
- API development (type-safe endpoints)
- Codebases migrating from JavaScript
