合并一相同节点

<p id="demo">单击按钮添加文本，单击另一个按钮标准化元素。</p>

<button onclick="addTextNode()">添加一个文本节点</button>

<button onclick="normPara()">规格化段落</button>

<script>

  function addTextNode() {

    var y = document.createTextNode(" Click again");

    var x = document.getElementById("demo");

    x.appendChild(y);

    var z = document.getElementById("cc");

    z.innerHTML = x.childNodes.length;

  }

​

  function normPara() {

    var x = document.getElementById("demo");

    x.normalize();

    var z = document.getElementById("cc");

    z.innerHTML = x.childNodes.length;

  }

</script>

<p>上面的段落有 <span id="cc">1</span>子节点。</p>