Destructuring Assignment Kya Hota Hai?

Destructuring ka Introduction

Destructuring assignment JavaScript (ES6) ka ek powerful feature hai jo humein arrays ya objects se values ko "unpack" karke alag-alag variables me assign karne ki suvidha deta hai. Yeh code ko chhota, clean, aur zyada readable banata hai.

1. Array Destructuring

Array destructuring se aap array ke elements ko unke index ke basis par variables me nikal sakte hain.

const numbers = [10, 20, 30];
const [a, b, c] = numbers;

console.log(a); // 10
console.log(b); // 20
console.log(c); // 30

Skipping Elements

Aap comma (,) ka use karke beech ke elements ko skip kar sakte hain.

const [first, , third] = [10, 20, 30];
console.log(first); // 10
console.log(third); // 30

Default Values

Agar array me value maujood nahi hai, toh aap ek default value de sakte hain.

const [x, y = 10] = [5];
console.log(x); // 5
console.log(y); // 10

2. Object Destructuring

Object destructuring se aap object ki properties ko unke naam (key) ke basis par variables me nikal sakte hain.

const person = {
  name: "Amit",
  age: 28,
  city: "Delhi"
};

const { name, age } = person;
console.log(name); // "Amit"
console.log(age); // 28

Renaming Variables

Aap colon (:) ka use karke property ko ek naye naam ke variable me store kar sakte hain.

const { name: userName, age: userAge } = person;
console.log(userName); // "Amit"

Default Values

Object me bhi aap default values de sakte hain.

const { city, country = "India" } = person;
console.log(city); // "Delhi"
console.log(country); // "India"

Destructuring in Function Parameters

Destructuring ka use function parameters ke saath karna bohot common aur useful hai. Isse aapko object se direct zaroori properties mil jaati hain.

function displayUser({ name, age }) {
  console.log(`User: ${name}, Age: ${age}`);
}

const user = { name: "Priya", age: 25 };
displayUser(user); // Output: User: Priya, Age: 25