Js实现Map对象，set对象

   
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>  

js实现set集合

<script type="text/javascript">

Array.prototype.distinct = function() {
  var x = [], r = [];
  for(var i = 0; i < this.length; i++) {
    x['_' + this[i]] = this[i];
  }
  for(var b in x) {
    if(typeof x[b] != 'function') {
      r.push(x[b]);
    }
  }
  return r;
}

window.onload = function() {
  var a = [ 1, 4, 2, 4, 3, 8, 10, 3, 9, 1, 9, 7, 111 ];
  var r = a.distinct();
  alert(a.join(','));
  alert(r.join(','));
}
</script>

JS判断数组是否重复

var ary = new Array("111","22","33","111");

var nary=ary.sort();

for(var i=0;i<ary.length;i++){

if (nary[i]==nary[i+1]){

alert("数组重复内容："+nary[i]);

}

}