js如何判斷一個數組里連續有相同的字符？

function isRepeat() {

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("數組中有重復元素：" + ary[i]);

break;

}

}

}