<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div>
<i></i>
<b></b>
<span></span>
</div>
<script>
// 1.封装函数 insertAfter()；功能类似 insertBefore();
Element.prototype.insertAfter=function (tragetNode,afterNODE) {
var beforeNode=afterNODE.nextElementSibling;
if (beforeNode==null){
afterNODE.appendChild(tragetNode)
}else {
beforeNode.appendChild(tragetNode)
}
}
</script>
</body>
</html>