​x
 
<!DOCTYPE html>
<html>
<head>
<style>
table, th, td {
  border: 1px solid black;
}
</style>
</head>
<body>
​
<h3>如何访问 THEAD 元素的演示</h3>
​
<table>
 <thead id="myTHead">
   <tr>
     <th>Header 1</th>
     <th>Header 2</th>
   </tr>
  </thead>
 <tbody>
   <tr>
     <td>Cell 1</td>
     <td>Cell 2</td>
   </tr>
   <tr>
     <td>Cell 3</td>
     <td>Cell 4</td>
   </tr>
  </tbody>
</table>
​
<p>单击该按钮可更改 THEAD 元素的样式。</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var x = document.getElementById("myTHead");
  x.style.color = "red";
}
</script>
​
</body>
</html>
​
​