JS 键值对

function Map() {
 this.keys = new Array();
 this.data = new Array();
 //添加键值对
this.set = function (key, value) {
 if (this.data[key] == null) {//如键不存在则身【键】数组添加键名
this.keys.push(value);
 }
 this.data[key] = value;//给键赋值
};
 //获取键对应的值
this.get = function (key) {
 return this.data[key];
 };
 //去除键值，(去除键数据中的键名及对应的值)
this.remove = function (key) {
 this.keys.remove(key);
 this.data[key] = null;
 };
 //判断键值元素是否为空
this.isEmpty = function () {
 return this.keys.length == 0;
 };
 //获取键值元素大小
this.size = function () {
 return this.keys.length;
 };
 }