ES6: Set 与 Map

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();