模拟一个HashTable类，包含有add、remove、contains、length方法

Question

[size=medium]如题，求教：模拟一个HashTable类，包含add、remove、contains、length方法？[/size]

Answer 1

[quote]
[code="js"]
function Hashtable()
{
this.container = new Object();

        /**//** put element */
        this.put = function (key, value) 
        {
            if (typeof (key) == "undefined")
            {
                return false;
            } 
            if (this.contains(key))
            {
                return false;
            } 
            this.container[key] = typeof (value) == "undefined" ? null : value;
            return true;
        };

        /**//** remove element */
        this.remove = function (key) 
        {
            delete this.container[key];
        };

        /**//** get size */
        this.size = function () 
        {
            var size = 0;
            for (var attr in this.container) 
            {
                size++;
            }
            return size;
        };

        /**//** get value by key */
        this.get = function (key) 
        {
            return this.container[key];
        };

        /**//** containts a key */
        this.contains = function (key) 
        {
            return typeof (this.container[key]) != "undefined";
        };

        /**//** clear all entrys */
        this.clear = function () 
        {
            for (var attr in this.container)
            {
                delete this.container[attr];
            }
        };

        /**//** hashTable 2 string */
        this.toString = function()
        {
            var str = "";
            for (var attr in this.container)
            {
                str += "," + attr + "=" + this.container[attr];
            }
            if(str.length>0)
            {
                str = str.substr(1, str.length);
            }
            return "{" + str + "}";
        };
    }

[/code]
[/quote]