let obj = { name: 'fulano' };
let map = new Map();

map.set(0, 1);
// map.set(1, 2)
map.set(2, 3);
map.set(1, 2);
map.set(obj, 10);

console.log(map);

let map = new Map([[0, 1], [2, 3], [1, 3]]);

console.log(map);

for (let [key, value] of map.entries()) {
  console.log(`${key} => ${value}`);
}

console.log(map.get(2));
console.log(map.get(obj));