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JavaScript Set & Map Objects Kya Hote Hai – What Are Set & Map Objects In JavaScript

JavaScript Set Object Kya Hote hai ?

JavaScript mein Set object ek aisa built-in data structure hai jo unique values ko store karta hai. Iska matlab hai ki Set ke andar duplicate values automatically hata di jaati hain. Jab aap new Set() se Set banate ho, to aap kisi bhi iterable jaise array se values pass kar sakte ho.

Set mein values insertion order mein store hoti hain, aur har value sirf ek baar hi hoti hai. Aap add(), delete(), has(), aur clear() jaise methods ka use karke Set ko modify kar sakte ho. Set ka use tab hota hai jab aapko unique values chahiye hoti hain bina repetition ke. Ye objects aur primitive values dono ko store kar sakta hai. Sets efficient aur fast hote hain for checking existence of elements.

Set ke Features:

  • Unique values only – Duplicate values automatically ignore ho jaate hain.
  • Insertion order maintain hoti hai – Jis order mein values add ki gayi hoti hain, usi order mein iterate hoti hain.
  • Iterable hota hai – Set par for...of aur forEach() use kar sakte ho.

Syntax :

let mySet = new Set();

Example:

let mySet = new Set();

mySet.add(10);
mySet.add(20);
mySet.add(10); // duplicate value, ignore ho jayegi

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

Set ke Important Methods:

Method Use
add(value) Set mein naya value add karta hai
delete(value) Value ko Set se remove karta hai
has(value) Check karta hai ki value Set mein hai ya nahi
clear() Set ko completely empty kar deta hai
size Set ke andar kitne elements hain, uska size return karta hai

Example of Methods:

let set1 = new Set([1, 2, 3]);

console.log(set1.has(2)); // true
set1.add(4); // Add 4
set1.delete(1); // Delete 1
console.log(set1.size); // 3
set1.clear(); // Empty Set
console.log(set1); // Set(0) {}

JavaScript Map Object :

JavaScript ka Map object ek built-in data structure hai jo key-value pairs store karta hai. Har key unique hoti hai, aur keys kisi bhi type ki ho sakti hain – jaise string, number, ya object.

Map ka advantage hai ki ye insertion order ko preserve karta hai, matlab jis order mein values add ki gayi hain, wahi order access karte waqt bhi milega.Map object mein values ko .set(key, value) se add kiya jata hai, aur .get(key) se access kiya jata hai. .has(key) check karta hai ki key exist karti hai ya nahi. Ye object se zyada efficient hota hai jab large scale data ya frequent insert/delete operations ki zarurat ho.

Map ke Features:

  • Key-value pairs store karta hai
  • Keys can be of any type – string, object, number, etc.
  • Insertion order maintain karta hai
  • Efficient searching and retrieval ke liye bana hai

Syntax:

let myMap = new Map();

Example:

let myMap = new Map();

myMap.set("name", "Sandeep");
myMap.set("age", 25);

console.log(myMap.get("name")); // Output: Sandeep

Map ke Important Methods:

Method Use
set(key, value) Naya key-value pair add karta hai
get(key) Diya gaya key ka value return karta hai
has(key) Check karta hai ki key Map mein exist karta hai ya nahi
delete(key) Diya gaya key-value pair remove karta hai
clear() Map ke saare elements hata deta hai
size Map mein kitne key-value pairs hain, wo batata hai

Example:

let user = new Map();

user.set("name", "Sandeep");
user.set("age", 26);
user.set(1, "one");
user.set(true, "yes");

console.log(user.get("name")); // Sandeep
console.log(user.has("age")); // true
console.log(user.size); // 4

user.delete(1);
console.log(user.size); // 3

user.clear();
console.log(user); // Map(0) {}

Map ka Real-life Use Case:

let loginData = new Map();

loginData.set("username", "admin");
loginData.set("password", "12345");

if (loginData.has("username")) {
  console.log("Login username: " + loginData.get("username"));
}

Set vs Map – Table for Quick Comparison:

Point Set Map
Structure Only values Key-value pairs
Duplicate values Not allowed Allowed (but keys unique)
Access Value-based Key-based
Key type N/A Any type (string, object, etc.)
Use case Unique items collection Storing config, settings, key-value data
Iteration Directly values Entries as [key, value] pairs

 

Set use karo jab aapko sirf unique values chahiyein, jaise ki duplicate remove karna ho.

Map use karo jab aapko key-value structure mein data store karna ho – jaise dictionary ya configuration.

Quiz: Test Your Knowledge on JavaScript Set & Map Objects

Bonus: Practical Application!

Aaj hi apne JavaScript project mein Set aur Map objects ka use karke dekhein!

JavaScript ke Set & Map objects ko sahi tareeke se samajhne ke liye inki key properties aur methods ka upayog karein jaise:

  • Set ke liye: add(), has(), delete(), size

  • Map ke liye: set(), get(), has(), delete(), size

Inka istemal karke aap apne data ko efficiently store aur manage kar sakte hain — bina duplicate values ke!

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