javascript案例 - W3xue在线HTML/CSS/JS运行工具

​x
 
<!DOCTYPE html>
<html>
<head>
<style>
table,th,td
{
border:1px solid black;
}
</style>
</head>
<body>
​
<h3>关于如何访问 COLGROUP 元素的一个演示</h3>
​
<table>
  <colgroup id="myColgroup" span="2" style="background:red"></colgroup>
  <tr>
    <th>ISBN</th>
    <th>Title</th>
    <th>Price</th>
  </tr>
  <tr>
    <td>3476896</td>
    <td>My first HTML</td>
    <td>$53</td>
  </tr>
  <tr>
    <td>5869207</td>
    <td>My first CSS</td>
    <td>$49</td>
  </tr>
</table>
​
<p>请点击按钮，来获得 COLGROUP 元素应该横跨的列数。</p>
​
<p id="demo"></p>
​
<button onclick="myFunction()">试一下</button>
​
<script>
function myFunction()
{
var x = document.getElementById("myColgroup").span;
document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>