Objects and maps compared

hashmaps.js

const arr = [["foo", "bar"], ["hello", "world"]];

// Create object from array of tuples
const obj = {}; arr.forEach(el => obj[el[0]] = el[1]);
const map = new Map(arr);

// Get object size
const objSize = Object.keys(obj).length;
const mapSize = map.size;

// Get array of values
const objValues = Object.keys(obj).map(key => obj[key]);
const mapValues = [...map.values()];

// Clear object
Object.keys(obj).forEach(key => delete obj[key]);
map.clear();