js中模仿java中的Map结构，用以存储键值对

/**
 * 为Array对象添加remove方法，删除制定值得元素
 * @param  {String} 数组元素值
 */
Array.prototype.remove = function(s) {     
    for (var i = 0; i < this.length; i++) {     
        if (s == this[i])     
            this.splice(i, 1);     
    }     
}
/**
 * 定义类型Java中的Map，存放键值对
 */
function Map(){
/**
 * 存放键的数组
 * @type {Array}
 */
this.keys = new Array();
/**
 * 存放数据
 * @type {Object}
 */
this.data = new Object();
/**
 * 放入一个键值对
 * @param  {String} key
 * @param  {Object} value
 */
this.put = function(key,value){
if(this.data[key] == null){
this.keys.push(key);
}
this.data[key] = value;
};
/**
 * 获取某键对应的值
 * @param  {String} key
 * @return {Object} value
 */
this.get = function(key){
return this.data[key];
};
/**
 * 删除一个键值对
 * @param  {String} key
 */
this.remove = function(key){
this.keys.remove(key);
this.data[key] = null;
};
/**
 * 遍历Map，执行处理函数
 * @param  {Function}
 */
this.each = function(fn){
if(typeof fn != 'function'){
return;
}
var len = this.keys.length;
for(var i = 0;i < len;i++){
var k = this.keys[i];
fn(k,this.data[k],i);
}
};
/**
 * 返回键值对数组(类似Java的entrySet)
 * @return {Object} 键值对对象{key,value}的数组
 */
this.entrys = function(){
var len = this.keys.length;
var entrys = new Array(len);
for(var i = 0;i < len;i++){
var tmp = this.keys[i];
entrys[i] = {
key : tmp,
value : this.data[tmp]
};
}
return entrys;
};
/**
 * 判断Map是否为空
 * @return {Boolean}
 */
this.isEmpty = function(){
return this.keys.length == 0;
};
/**
 * 获取键值对数量
 * @return {Number}
 */
this.size = function(){
return this.keys.length;
};
/**
 * 重写toString
 * @return {String}
 */
this.toString = function(){
var s = "{";
for(var i = 0;i < this.keys.length;i++,s+=','){
var k = this.keys[i];
s += k + "=" + this.data[k];
}
s += "}";
return s;
};
}

function testMap(){     
    var m = new Map();     
    m.put('key1','Comtop');     
    m.put('key2','南方电网');     
    m.put('key3','景新花园');     
    alert("init:"+m);     
         
    m.put('key1','康拓普');     
    alert("set key1:"+m);     
         
    m.remove("key2");     
    alert("remove key2: "+m);     
         
    var s ="";     
    m.each(function(key,value,index){     
        s += index+":"+ key+"="+value+"/n";     
    });     
    alert(s);

    var es = m.entrys();
    for(var i = 0;i < es.length;i++){
    var e = es[i];
    alert(e.key + "==" + e.value);
    }
}   

testMap();