Type Alias (টাইপ অ্যালিয়াস)

type UserId = string;
type Score = number;

let userA: UserId = "u-101";
let marks: Score = 95;

type User = {
  name: string;
  age: number;
  email?: string;
  readonly id: number;
};

const user: User = {
  id: 1,
  name: "রহিম",
  age: 28,
};

type Formatter = (value: string) => string;

const upper: Formatter = (value) => value.toUpperCase();
const reverse: Formatter = (value) => value.split("").reverse().join("");

console.log(upper("bangla"));    // BANGLA

type ID = string | number;
type Status = "pending" | "active" | "blocked";

function printId(id: ID): void {
  console.log("ID:", id);
}

printId("a-1");
printId(10);
// printId(true);   // ❌ boolean যাবে না

type HasName = { name: string };
type HasAge = { age: number };

type Person = HasName & HasAge;

const person: Person = {
  name: "রহিম",
  age: 28,
};

type Coordinate = { x: number; y: number };

function moveTo(place: Coordinate): void {
  console.log(`যাচ্ছি ${place.x}, ${place.y}`);
}

function distance(a: Coordinate, b: Coordinate): number {
  return Math.hypot(a.x - b.x, a.y - b.y);
}