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 aap ne 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.