js实现javaMap对象

<script>
/*js实现map功能*/
function Map()
{
var struct = function(key, value)
{
this.key = key;
this.value = value;
}
var put = function(key, value)
{
for (var i = 0; i < this.arr.length; i++)
{
if ( this.arr[i].key === key )
{
this.arr[i].value = value;
return;
}
}
this.arr[this.arr.length] = new struct(key, value);
}

var get = function(key)
{
for (var i = 0; i < this.arr.length; i++)
{
if ( this.arr[i].key === key )
{
return this.arr[i].value;
}
}
return null;
}

var remove = function(key)
{
var v;
for (var i = 0; i < this.arr.length; i++)
{
v = this.arr.pop();
if ( v.key === key )
{
continue;
}
this.arr.unshift(v);
}
}
var size = function()
{
return this.arr.length;
}
var isEmpty = function()
{
return this.arr.length <= 0;
}
this.arr = new Array();
this.get = get;
this.put = put;
this.remove = remove;
this.size = size;
this.isEmpty = isEmpty;
}

</script>

<script>
var map = new Map();
map.put("re","redhacker");
map.put("re","redhacker2");
map.put("do","douguoqiang");
map.put("gq","dougq");
alert("map的大小为：" + map.size())
alert("key为re的map中存储的对象为：" + map.get("re"));
map.remove("re");
alert("移除key为re的对象后，获取key为re的map中存储的对象为：" + map.get("re"));
alert("map移除一个元素后的大小为：" + map.size());
alert("map是否是一个空map:" + map.isEmpty());
</script>