What is the difference between Map and Set in JavaScript?

Map and Set are collections in JavaScript, but they serve different purposes:

• Map is a collection of key-value pairs. Keys can be of any type (objects, primitives). Map maintains the insertion order of elements and allows quick retrieval of values by key.

• Set is a collection of unique values. It stores only unique elements, without keys, and also maintains the insertion order.

Example:

const map = new Map();
map.set('key1', 'value1');
map.set({}, 'value2');

const set = new Set();
set.add('value1');
set.add('value2');
set.add('value1'); // will not be added again, as it already exists

console.log(map.get('key1')); // 'value1'
console.log(set.has('value1')); // true

Summary:

• Map — for storing key-value pairs.
• Set — for storing unique values without keys.