【LeetCode热题100（35/100）】LRU 缓存

题目地址：链接
思路： 利用 this.map.keys() 按照顺序存储特性并且 O(1) 时间复杂度完成存取，可以很好完成题目，并且 get 和 put 时间复杂度都为 O(1)

当前js 代码不能通过所有案例，有大佬能解释一下吗?

/*** @param {number} capacity*/
var LRUCache = function(capacity) {this.capacity = capacity;this.map = new Map();
};/** * @param {number} key* @return {number}*/
LRUCache.prototype.get = function(key) {let ans = -1;if(this.map.has(key)) {ans = this.map.get(key);this.map.delete(key);this.map.set(key, ans);}return ans;
};/** * @param {number} key * @param {number} value* @return {void}*/
LRUCache.prototype.put = function(key, value) {if(this.map.has(key)) {this.map.delete(key);}if(this.map.size >= this.capacity) {let oldkey = this.map.keys().next().value;this.map.delete(oldkey);}this.map.set(key, value);
};/** * Your LRUCache object will be instantiated and called as such:* var obj = new LRUCache(capacity)* var param_1 = obj.get(key)* obj.put(key,value)*/