代码示例：（标识：jsck_document_normalize）
<!DOCTYPE html>
<html>
<body onload="normPara()">
<h1>Document 对象</h1>
<h2>normalize() 方法</h2>
<button onclick="addTextNode()">添加文本节点</button>
<button onclick="normPara()">规范化此文档</button>
<p>此文档拥有 <span id="cc" style="font-size:20px">1</span> 个子节点。</p>
<script>
function addTextNode() {
const textNode= document.createTextNode("再次点击。");
const body = document.body;
body.appendChild(textNode);
const cc = document.getElementById("cc");
cc.innerHTML = body.childNodes.length;
}
function normPara() {
document.normalize();
const body = document.body;
const cc = document.getElementById("cc");
cc.innerHTML = body.childNodes.length;
}
</script>
</body>
</html>
