js去重复和取重复数据

js数组中取重复数据的方法：
    方法一：去重复数据
    <script>
        Array.prototype.distinct=function(){
        var a=[],b=[];
        for(var prop in this){
           var d = this[prop];
           if (d===a[prop]) continue; //防止循环到prototype
           if (b[d]!=1){
            a.push(d);
            b[d]=1;
           }
        }
        return a;
        }
        var x=['a','b','c','d','b','a','e','a','b','c','d','b','a','e'];
        document.write('原始数组:'+x);
        document.write("<br />");
        document.write('去重复后:'+x.distinct());
    </script>
方法二：取重复数据
    <script type="text/javascript">
    Array.prototype.distinct=function(){
       var a=[],b=[],c=[],d=[];
       for(var prop in this){
        var d = this[prop];
        if (d===a[prop])
        {
        continue;
        }//防止循环到prototype
        if (b[d]!=1){
         a.push(d);
         b[d]=1;
        }
        else {

         c.push(d);
         d[d]=1;
        }
       }
       //return a;
       return c.distinct1();
    }
    Array.prototype.distinct1=function(){
    var a=[],b=[];
    for(var prop in this){
       var d = this[prop];
       if (d===a[prop]) continue; //防止循环到prototype
       if (b[d]!=1){
        a.push(d);
        b[d]=1;
       }
    }
    return a;
    }
    var x=['a','b','c','d','b','a','e','a','b','c','d','b','a','e','f','f','g'];
    document.write('原始数组:'+x);
    document.write("<br />");
    document.write('去重复后:'+x.distinct());
    </script>