jQuery判断网页中的id是否有重复的

From:http://blog.csdn.net/china_skag/article/details/6915323判断网页中的ID是否有重复的:指定ID判断

$(function(){

    $("body [id]").each(function(){

         var ids = $(this).attr("id");

          if( $("body [id="+ids+"]").length >= 2 ){

                         alert("id为"+ids+" 的重复了。");

        }

    });

})  

判断网页中的ID是否有重复的：不指定ID判断

function chkid() {

        var did = {}

        divs = document.getElementsByTagName("*");

        for (var i = 0, l = divs.length; i < l; i++) {

            divs[i].getAttribute("id")

                ? did[divs[i].getAttribute("id")] === undefined

                    ? did[divs[i].getAttribute("id")] = 0

                    : did[divs[i].getAttribute("id")]++

                : 0;

        }

        for (var i in did) {

            did[i]

                ? alert("id " + i + "重复了" + (did[i] + 1) + "次")

                : 0;

        }

    }