Arrow Functions

TypeScript mein arrow functions bilkul JavaScript ki tarah kaam karte hain, bas unke parameters aur return value par same type annotations available hote hain.

const square = (x: number): number => x * x;
console.log(square(5));

25

Inferred return types

Aapko return type ko explicitly annotate karne ki zaroorat nahi hai — TypeScript ise function body se infer kar leta hai, aur phir bhi har call site par usko bilkul waise hi enforce karta hai jaise aapne khud likha ho.

const numbers: number[] = [1, 2, 3, 4, 5];
const squared = numbers.map((x) => x * x);
console.log(squared);

[ 1, 4, 9, 16, 25 ]

Aage: enums — related constant values ka ek naam wala set.