返回body元素的节点类型

<p id="demo">单击按钮获取一个body元素子节点的节点类型。</p>

<button onclick="myFunction()">点我</button>

<script>

  function myFunction() {

    var txt = "";

    var c = document.body.childNodes;

    for (i = 0; i < c.length; i++) {

      txt = txt + c[i].nodeType + "<br>";

    };

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

    x.innerHTML = txt;

  }

</script>

<p><strong>注意:</strong> 空格元素是文本，文本是节点.</p>