现代浏览器原生js获取id号方法

<div id="tests" class="a b c" style="color:#f00">123</div>

var test = tests.firstChild.nodeValue;
tests = tests.childNodes[0];
tests.insertData(0,789);//从前插入789var t2 = document.querySelector("#tests");//获取id号console.log(t2.mozMatchesSelector(".c"));////t2是否含有c的classname

function hasClass(ele,txt){
var ary = ["matchesSelector","mozMatchesSelector","msMatchesSelector","webkitMatchesSelector"],
i = ary.length-1,
t = false;for(;i>=0;i--){if(typeof ele[ary[i]] == "function"){if(ele[ary[i]].call(ele,txt)){
t = true;
}}}return t;}
console.log(hasClass(t2,".a"));