10.5 插入节点
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
function insertNode() {
var p1 = document.getElementById("p1");
var textNode = document.createTextNode("insertNode");
var element = document.createElement("p");
element.appendChild(textNode);
p1.parentNode.insertBefore(element,p1);
}
</script>
</head>
<body>
<p>JavaScript</p>
<div id="testDiv">
<p id="p1">1</p>
<p>2</p>
<p>3</p>
</div>
<button onclick="insertNode()">click</button>
</body>
</html>