Js 键值对实现

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;
};
}