Functions मध्ये Types

// Parameters + return type
function greet(name: string, city: string): string {
  return `नमस्कार ${name}, ${city} मधून!`;
}

// Optional parameter (?)
function createUser(name: string, age?: number): string {
  return age ? `${name}, वय: ${age}` : name;
}

// Default parameter
function welcome(name: string, lang: string = "Marathi"): string {
  return `Welcome to ${lang} tutorial, ${name}!`;
}

// Rest parameters
function sum(...nums: number[]): number {
  return nums.reduce((a, b) => a + b, 0);
}
console.log(sum(1, 2, 3, 4, 5)); // 15

// Arrow function with types
const multiply = (a: number, b: number): number => a * b;

// Function type as variable type
let mathOperation: (x: number, y: number) => number;
mathOperation = multiply;
mathOperation = (a, b) => a + b; // ✅

// Void return
const log = (msg: string): void => {
  console.log(msg);
};