显示 <meta> 标签 name 属性的 - 在线编辑器

          <!DOCTYPE html>
<html>
<body>
  <head>
    <meta name="description" content="编程技术入门教程">
    <meta name="keywords" content="HTML5,CSS,JavaScript">
    <meta name="author" content="mifengjc">
  </head>

  <p>点击按钮返回所有 meta 元素的name属性的值。</p>

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

  <p id="demo"></p>

  <script>
    function myFunction() {
      var x = document.getElementsByTagName("META");
      var txt = "";
      var i;
      for (i = 0; i < x.length; i++) {
        txt = txt + "第 " + (i + 1) + " 个 meta 标签 name 属性值 : " + x[i].name + "<br>";
      }
      document.getElementById("demo").innerHTML = txt;
    }
  </script>

</body>
</html>
        