简单教程
提交运行
代码编辑器：
<style> table,th,td{ border:1px solid black; } </style> <table> <colgroup> <col id="myCol" span="2" style="background-color:red"> <col style="background-color:yellow"> </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>点击按钮返回列中span属性的值</p> <p id="demo"></p> <button onclick="myFunction()">点我</button> <script> function myFunction(){ var x = document.getElementById("myCol").span; document.getElementById("demo").innerHTML=x; } </script>
运行结果：