<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<h1>标题1</h1>
<h1>标题2</h1>
<script type="text/javascript">
var body = document.querySelector('body')
var hbiaoti2 = document.querySelectorAll('h1')[1]
var newDiv = document.createElement('p')
newDiv.innerHTML = '这是一个段落'
//这是替换
// body.replaceChild(newDiv,hbiaot
//插入到某个元素的前面
body.insertBefore(newDiv,hbiaoti2)
//插入到某个元素的后面,原生JS里没有insertAfter
body.insertBefore(newDiv,hbiaoti2.nextElementSibling)
</script>
</body>
</html>