创建标签然后对标签操作
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
abc{
width: 20px;
height: 20px;
background-color: red;
display: block;
}
</style>
</head>
<body>
<div id="box">
<p id="child1">大壮</p>
</div>
<script type="text/javascript">
var oDiv = document.getElementById('box');
// var oP = document.createElement('abc');
// oDiv.appendChild(oP);
var op1 = document.getElementById('child1');
var op2 = document.createElement('p');
op2.innerText = '热狗';
oDiv.insertBefore(op2, op1);
</script>
</body>
</html>