What is it

Object that holds key-value pairs and remembers the original insertion order of the keys

Map can only have one unique key

const map1 = new Map();

map1.set('a', 1);
map1.set('b', 2);
map1.set('c', 3);

console.log(map1.get('a')); // 1

map1.set('a', 97);
console.log(map1.get('a')); // 97
console.log(map1.size); // 3

map1.delete('b');
console.log(map1.size); // 2

Cloning Map

const original = new Map([
  [1, 'one']
]);

const clonedMap = new Map(original);

console.log(clonedMap.get(1)); // one
console.log(original === clonedMap); // false