CodingBlast blog - Set, Map - https://codingblast.com/javascript-set-map/

Set.js

let set = new Set([3, 5, true, 'This is a string, obviously.']);

for (let item of set.values()) {
  console.log(item);
}

console.log('Adding a new value');
set.add(5);

for (let item of set.values()) {
  console.log(item);
}