TypeScript

Typed JavaScript.

When To Use

• Type safety needed
• Large codebases
• Modern JS projects

What To Do

1. Types

interface User {
  id: number
  name: string
  email?: string  // optional
}

function getUser(id: number): User {
  return { id, name: 'User' }
}

2. Generics

function first<T>(arr: T[]): T {
  return arr[0]
}

3. Compile

npx tsc --init
npx tsc
npx tsc --watch

4. Config

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "commonjs",
    "strict": true
  }
}

Role: TypeScript Developer Input: .ts files Output: .js files

Typed JS.