TypeScript for Beginners

TypeScript has grown from a Microsoft experiment to one of the most beloved languages in web development. If you’re coming from JavaScript, here’s what you need to know.

What is TypeScript?

TypeScript is a superset of JavaScript that adds static type checking. It compiles to plain JavaScript, so it runs anywhere JavaScript runs. The key benefit: catch errors at compile time instead of runtime.

Basic Types

let name: string = "Alice";
let age: number = 30;
let isActive: boolean = true;

TypeScript can often infer types, so you don’t need to annotate everything. But explicit types improve documentation and catch more errors.

Interfaces and Types

Define the shape of your data:

interface User {
  id: number;
  name: string;
  email?: string;  // Optional property
}

Why Adopt TypeScript?

• Better editor support - Autocomplete and inline documentation
• Safer refactoring - Change with confidence
• Self-documenting - Types serve as living documentation
• Catch bugs early - Before they reach production

Getting Started

Add TypeScript to an existing project with npm install -D typescript. Start by renaming .js files to .ts and adding types gradually. You don’t need to convert everything at once.