JavaScript Set & Map Objects Kya Hote Hai?

1. Set Object

JavaScript mein Set ek special collection hai jo sirf unique values ko hi store karta hai. Iska matlab hai ki agar aap ek hi value ko Set mein baar-baar add karne ki koshish karenge, to woh sirf ek hi baar store hogi.

Key Features of Set:

• Unique Values Only: Duplicate values automatically ignore ho jaate hain.
• Any Data Type: Aap isme primitive values (string, number) aur objects dono store kar sakte hain.
• Iterable: Aap ispar for...of loop ya forEach() method ka use kar sakte hain.

let mySet = new Set();
mySet.add(10);
mySet.add(20);
mySet.add(10); // Yeh duplicate hai, isliye ignore ho jayega

console.log(mySet); // Output: Set(2) { 10, 20 }

// Array se duplicate hatana
const numbers = [1, 2, 2, 3, 4, 3];
const uniqueNumbers = [...new Set(numbers)];
console.log(uniqueNumbers); // [1, 2, 3, 4]

2. Map Object

JavaScript ka Map object key-value pairs ko store karta hai. Yeh plain JavaScript object { } se zyada powerful aur flexible hai kyunki isme keys kisi bhi data type (object, function, etc.) ki ho sakti hain, jabki plain objects me keys sirf strings ya symbols ho sakti hain.

Key Features of Map:

• Any Type of Keys: Keys numbers, strings, objects, ya functions bhi ho sakti hain.
• Insertion Order: Map keys ka insertion order yaad rakhta hai.
• Better Performance: Frequent additions aur deletions ke liye yeh plain objects se zyada efficient hai.

let myMap = new Map();

let keyString = 'a string';
let keyObj = {};
let keyFunc = function() {};

// keys set karna
myMap.set(keyString, "Value for a string");
myMap.set(keyObj, "Value for an object");
myMap.set(keyFunc, "Value for a function");

console.log(myMap.get(keyString)); // "Value for a string"
console.log(myMap.size); // 3

Set vs. Map: Quick Comparison