JS实现HashMap

/**
* *********  操作实例  **************
*	var map = new HashMap();
*	map.put("key1","Value1");
*	map.put("key2","Value2");
*	map.put("key3","Value3");
*	map.put("key4","Value4");
*	map.put("key5","Value5");
*	alert("size："+map.size()+" key1："+map.get("key1"));
*	map.remove("key1");
*	map.put("key3","newValue");
*	var values = map.values();
*	for(var i in values){
*		document.write(i+"："+values[i]+"   ");
*	}
*	document.write("<br>");
*	var keySet = map.keySet();
*	for(var i in keySet){
*		document.write(i+"："+keySet[i]+"  ");
*	}
*	alert(map.isEmpty());
*/

function HashMap(){
	//定义长度
	var length = 0;
	//创建一个对象
	var obj = new Object();

	/**
	* 判断Map是否为空
	*/
	this.isEmpty = function(){
		return length == 0;
	};

	/**
	* 判断对象中是否包含给定Key
	*/
	this.containsKey=function(key){
		return (key in obj);
	};

	/**
	* 判断对象中是否包含给定的Value
	*/
	this.containsValue=function(value){
		for(var key in obj){
			if(obj[key] == value){
				return true;
			}
		}
		return false;
	};

	/**
	*向map中添加数据
	*/
	this.put=function(key,value){
		if(!this.containsKey(key)){
			length++;
		}
		obj[key] = value;
	};

	/**
	* 根据给定的Key获得Value
	*/
	this.get=function(key){
		return this.containsKey(key)?obj[key]:null;
	};

	/**
	* 根据给定的Key删除一个值
	*/
	this.remove=function(key){
		if(this.containsKey(key)&&(delete obj[key])){
			length--;
		}
	};

	/**
	* 获得Map中的所有Value
	*/
	this.values=function(){
		var _values= new Array();
		for(var key in obj){
			_values.push(obj[key]);
		}
		return _values;
	};

	/**
	* 获得Map中的所有Key
	*/
	this.keySet=function(){
		var _keys = new Array();
		for(var key in obj){
			_keys.push(key);
		}
		return _keys;
	};

	/**
	* 获得Map的长度
	*/
	this.size = function(){
		return length;
	};

	/**
	* 清空Map
	*/
	this.clear = function(){
		length = 0;
		obj = new Object();
	};
}