Set

  • let my_set = new Set();
  • let my_set = new Set([1, 1, 2, 2]);
  • my_set.add(5);
  • my_set.delete(5);
  • my_set.has(5);
  • my_set.forEach(function(value){});
  • let my_set = WeakSet() // 只允许对象作为set的元素，便于垃圾回收

Map

  • let my_map = new Map();
  • let map = new Map([[“name”, “Nicholas”], [“age”, 25]]);
  • my_map.set(key, value);
  • my_map.get(key)
  • my_map.has(key)
  • my_map.delete(key);
  • my_map.clear();
  • my_map.size;
  • my_map.forEach(function(value, key, ownerMap) { console.log(key + “ “ + value); console.log(ownerMap === map); });
  • let map = new WeakMap();