<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<script>
window.onload = function(){
var oUl = document.getElementById("ul1");
//ie 6-8 高版本不支持
// oUl.firstChild.style.background = "red";
//高版本浏览器
// oUl.firstElementChild.style.background = "red";
//兼容写法
if(oUl.firstElementChild)
{
oUl.firstElementChild.style.background = "red";
}else{
oUl.firstChild.style.background = "red";
}
}
</script>
<body>
<ul id="ul1">
<li>1</li>
<li>2</li>
</ul>
</body>
</html>
lastChild lastElementChild nextSibling nextElementSibing previousSibling previousElementSibling 一样使用