// JavaScript Document
function HashMap()
{
    /** Map 大小 **/
    var size = 0;
    /** 對象 **/
    var entry = new Object();
    
    /** 存 **/
    this.put = function (key , value)
    {
        if(!this.containsKey(key))
        {
            size ++ ;
        }
        entry[key] = value;
    }
    
    /** 取 **/
    this.get = function (key)
    {
        return this.containsKey(key) ? entry[key] : null;
    }
    
    /** 刪除 **/
    this.remove = function ( key )
    {
        if( this.containsKey(key) && ( delete entry[key] ) )
        {
            size --;
        }
    }
    
    /** 是否包含 Key **/
    this.containsKey = function ( key )
    {
        return (key in entry);
    }
    
    /** 是否包含 Value **/
    this.containsValue = function ( value )
    {
        for(var prop in entry)
        {
            if(entry[prop] == value)
            {
                return true;
            }
        }
        return false;
    }
    
    /** 所有 Value **/
    this.values = function ()
    {
        var values = new Array();
        for(var prop in entry)
        {
            values.push(entry[prop]);
        }
        return values;
    }
    
    /** 所有 Key **/
    this.keys = function ()
    {
        var keys = new Array();
        for(var prop in entry)
        {
            keys.push(prop);
        }
        return keys;
    }
    
    /** Map Size **/
    this.size = function ()
    {
        return size;
    }
    
    /* 清空 */
    this.clear = function ()
    {
        size = 0;
        entry = new Object();
    }
}