js模拟hashtable的简单实例

代码如下:
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]; } }
}

代码如下:
// 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