Learn TYPESCRIPT with Real Code Examples

TypeScript adds optional static typing to JavaScript for safer, more predictable code.

It improves developer experience with IntelliSense, auto-completion, and real-time error checking.

Fully compatible with existing JavaScript code, libraries, frameworks, and browsers.

Optional static typing

Structural type system

Classes, interfaces, and generics

Async/await and promises

Enums, namespaces, and modules

Basic types and inference

Interfaces and type aliases

Functions and generics

Classes and inheritance

Union/intersection types

Modules and namespaces

src/ for TypeScript source

dist/ for compiled JavaScript

tsconfig.json for compiler options

package.json for scripts and dependencies

types/ for type declarations

Write code in .ts files

Transpile using tsc

Run output JavaScript with Node.js or browser

Use ts-node for direct execution

Bundle with Webpack, Vite, or ESBuild

Beginner: Basic scripts and utilities

Intermediate: React + TS applications

Advanced: Backend APIs with NestJS

Expert: Complex type-level programming

Safer than JavaScript

More flexible than Java

Higher DX than C# for web apps

Not as fast as Go/Rust for backend

TypeScript 1.0 (2014) – First stable release

TypeScript 2.x – Strict mode, async/await

TypeScript 3.x – Project references, mapped types

TypeScript 4.x – Variadic tuples, template literal types

Type Inference: Compiler guesses types

Union Type: Value can be one of many types

Interface: Structural contract of a shape

Decorator: Metadata annotation (experimental)