02-UsingSets.js

let set = new Set();

set.add(1);
console.log(set.values()); //outputs [1]
console.log(set.has(1));   //outputs true
console.log(set.size());   //outputs 1

set.add(2);
console.log(set.values()); //outputs [1, 2]
console.log(set.has(2));   //true
console.log(set.size());   //2
console.log(set.sizeLegacy());   //3

set.delete(1);
console.log(set.values()); //outputs [2]

set.delete(2);
console.log(set.values()); //outputs []