Maps

var map = new Map(); map.set('spec', '2015'); map.set('year', '2015'); // use `.get()` to retrieve items console.log(map.get('spec')); // 2015 // iteration for (var [key, value] of map) { console.log(key + ': ' + value); } // helper functions map.entries(); // Gives you all the entries in map map.keys(); // Gives you all the keys in map map.values(); // Gets you the values stored in map map.has(keyName); // Checks if a map has specified key or not map.delete(keyName); // Replaces the value having the provided key map.size; // Gives you the size of map map.clear(); // Clears all the collection