js map

<mce:script type="text/javascript"><!--

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;
}
// --></mce:script>

<mce:script type="text/javascript"><!--
var map = new Map();
map.put("re","redhacker");
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());
// --></mce:script>