# 标准内置对象—Map

var map = new Map();

map.set(1, "value1");
map.set({ key: 2 }, "value2");
map.set("key3", "value3");

console.log(map.get(1)); // value1。此时第二个不能取出来，除非在添加时先声明一个变量

console.log(map.has("key3")); // true

map.forEach((item, index, map) => {
  console.log(item);
});

for (const [key, value] of map) {
  console.log(key, value);
}

var iterator = map.entries();
console.log(iterator.next()); // {value: Array(2), done: false}
console.log(iterator.next()); // {value: Array(2), done: false}
console.log(iterator.next()); // {value: Array(2), done: false}
console.log(iterator.next()); // {value: undefined, done: true}

// keys values 不介绍了

map.delete("key3");
console.log(map);

map.clear();