ES6 — set, map, weak

Sets and maps will be (are) finally available in ES6! No more spartan way to manipulate data structures. This chapter explains how we can deal with Map, Set, WeakMap and WeakSet. MapMaps are a store for key / value pairs. Key and value could be a primitives or object references. Let’s create a map: let map = new Map(), val2 = 'val2', val3 = { key: 'value' };map.set(0, 'val1'); map.set('1', val2);