function Hashtable()//自定义hashtable {     this._hash = new Object();     this.add = function(key, value) {         if (typeof (key) != "undefined") {             if (this.contains(key) == false) {                 this._hash[key] = typeof (value) == "undefined" ? null : value;                 return true;             } else {                 return false;             }         } else {             return false;         }     }     this.remove = function(key) { delete this._hash[key]; }     this.count = function() { var i = 0; for (var k in this._hash) { i++; } return i; }     this.items = function(key) { return this._hash[key]; }     this.contains = function(key) { return typeof (this._hash[key]) != "undefined"; }     this.clear = function() { for (var k in this._hash) { delete this._hash[k]; } } }

// js哈希表 function HashTable() {     this.ObjArr = {};     this.Count = 0;     //添加     this.Add = function(key, value) {         if (this.ObjArr.hasOwnProperty(key)) {             return false; //如果键已经存在，不添加         }         else {             this.ObjArr[key] = value;             this.Count++;             return true;         }     }     //是否包含某项     this.Contains = function(key) {         return this.ObjArr.hasOwnProperty(key);     }     //取某一项 其实等价于this.ObjArr[key]     this.GetValue = function(key) {         if (this.Contains(key)) {             return this.ObjArr[key];         }         else {             throw Error("Hashtable not cotains the key: " + String(key)); //脚本错误             //return;         }     }     //移除     this.Remove = function(key) {         if (this.Contains(key)) {             delete this.ObjArr[key];             this.Count--;         }     }     //清空     this.Clear = function() {         this.ObjArr = {}; this.Count = 0;     } } 测试代码: //员工 function employee(id, userName) {     this.id = id;     this.userName = userName; } function test() {     var ht = new HashTable();     var tmpEmployee = null;     for (var i = 1; i < 6; i++) {         tmpEmployee = new employee(i, "Employee_" + i);         ht.Add(i, tmpEmployee);     }     for (var i = 1; i <= ht.Count; i++) {         alert(ht.GetValue(i).userName); //其实等价于ht.ObjArr[i].userName         //alert(ht.ObjArr[i].userName);     }     ht.Remove(1);     alert(ht.Contains(1)); //false     alert(ht.Contains(2)); //true     //alert(ht.GetValue(1)); //异常     var result = ht.GetValue(2);     if (result != null) {         alert("Employee Id:" + result.id + ";UserName:" + result.userName);     }     ht.Add(2, "这一个key已经存在!"); //Add无效     //ht.Clear(); //清空     alert(ht.Count); }