下面的例子获取 id="intro" 的元素 - 在线编辑器

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
</head>
<body>

  <p id="intro">Hello World!</p>
  <p>这个实例演示了 <b>getElementById</b> 方法!</p>

  <script>
    x = document.getElementById("intro");
    document.write("<p>段落的文本为: " + x.innerHTML + "</p>");
  </script>

</body>
</html>
​x
 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
</head>
<body>
​
  <p id="intro">Hello World!</p>
  <p>这个实例演示了 <b>getElementById</b> 方法!</p>
​
  <script>
    x = document.getElementById("intro");
    document.write("<p>段落的文本为: " + x.innerHTML + "</p>");
  </script>
​
</body>
</html>