html table，表格合并单元格colspan，rowspan

代码如下：

<table border="1" style="width: 500px;">
    <tr>
        <th>标题</th>
        <th>标题</th>
        <th>标题</th>
    </tr>
    <tr >
        <td rowspan="2">11</td>
        <td>22</td>
        <td>33</td>
    </tr>
    <tr>
        <td>22</td>
        <td>33</td>
    </tr>
    <tr>
        <td >11</td>
        <td colspan=2>22</td>
    </tr>
</table>

效果如下：

如果是合并单元格使用饿colspan=2就把下面的td注释掉这一个td占两行，
不然显示出来显得很怪

<tr>
    <td>11</td>
    <td colspan=2>22</td>
</tr>

不然写成下面这种

<tr>
    <td>11</td>
    <td colspan=2>22</td>
    <td></td>
</tr>

如果是合并行的话，rowspan=”2”
要把下面一行的td干掉一个

<tr>
    <td rowspan="2">11</td>
    <td>22</td>
    <td>33</td>
</tr>
<tr>
    <td>22</td>
    <td>33</td>
</tr>

实现一个这样的合并：

代码如下：

<table border="1" style="width: 500px;">
            <tr>
                <th>标题</th>
                <th>标题</th>
                <th>标题</th>
            </tr>
            <tr >
                <td rowspan="2">11</td>
                <td>22</td>
                <td>33</td>
            </tr>
            <tr>
                <td>22</td>
                <td>33</td>
            </tr>
            <tr>
                <td >11</td>
                <td colspan=2>22</td>
            </tr>
            <tr>
                <td >11</td>
                <td >22</td>
                <td >33</td>
            </tr>
            <tr>
                <td colspan=2>11</td>
                <td rowspan="2">22</td>
            </tr>
            <tr>
                <td >11</td>
                <td >11</td>
            </tr>
            <tr></tr>
        </table>