What is the relationship between Map and Set collections in JavaScript?

In JavaScript, the collections Map and Set are closely related in that both are designed to store unique values, but they operate with them differently:

• Set is a collection of unique values without keys. It only stores unique elements, such as numbers or strings, and does not allow duplicate values.

• Map is a collection of key-value pairs, where keys can be of any type, including objects. Map allows storing and quickly retrieving values by key.

The relationship between them is that Set can be viewed as a special case of Map, where keys and values are the same. For example, internally, Set can be represented as a Map where the keys are the set elements, and the values are irrelevant or equal to the keys themselves.

Example:

const set = new Set([1, 2, 3]);
const map = new Map([[1, 1], [2, 2], [3, 3]]);

console.log(set.has(2)); // true
console.log(map.has(2)); // true

Thus, Map and Set complement each other, providing convenient data structures for different tasks: Map for key-value pairs, Set for unique values.