Javascript - Basics of using built-in Set method

JavaScript Set - Concise Notes 🚀

🔹 What is a Set?

A Set is a built-in JavaScript object that stores unique values (no duplicates).

🔹 Creating a Set

const mySet = new Set([1, 2, 3, 4, 5]);

🔹 Key Methods

Method	Description	Example Usage
.add(value)	Adds a value to the Set	mySet.add(6);
.delete(value)	Removes a value	mySet.delete(3);
.has(value)	Checks if value exists	mySet.has(2); // true
.clear()	Removes all elements	mySet.clear();
.size	Returns the number of elements	mySet.size; // 5

🔹 Iterating Over a Set

mySet.forEach(value => console.log(value)); // Loop using forEach
for (let value of mySet) console.log(value); // Loop using for...of

🔹 Convert Set to Array

const numArray = [...mySet];

🔹 Convert Array to Set (Remove Duplicates)

const uniqueNums = new Set([1, 2, 2, 3, 4]); // {1, 2, 3, 4}

🔹 When to Use a Set?

✅ Fast lookups (O(1))

✅ Removing duplicates

✅ Tracking unique values

🚀 Best for performance when working with unique data!