javascript hashtable(转)

 

// 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; 
    } 
} 


//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); 
}