JS判断数组中是否有重复值得三种方法

转：http://blog.csdn.net/ynztpwl/article/details/7406562

我用的是第三种方法

方法一:

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

var s = ary.join(",")+",";

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

 if(s.replace(ary[i]+",","").indexOf(ary[i]+",")>-1) {

  alert("数组中有重复元素：" + ary[i]);

  break;

 }

}
方法二:

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]);

 }

}

方法三: 内陆运输

function isRepeat(arr){

     var hash = {};

     for(var i in arr) {

         if(hash[arr[i]])

              return true;

         hash[arr[i]] = true;

     }

     return false;

}