js判断数组中是否有相同元素

js判断数组中是否有相同元素

Js判断数组是否存在重复元素的三种方法

方法一:

varary = new Array("111","22","33","111");

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

for(var i=0;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:

varary = new Array("111","22","33","111");

var nary=ary.sort();

for(var i=0;i

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

alert("数组重复内容："+nary[i]);

}

}

方法三:

functionisRepeat(arr){

var hash = {};

for(var i in arr) {

if(hash[arr[i]])

return true;

hash[arr[i]] = true;

}

return false;

}