Grouping Table Columns: The col Element

for better management and accessibility.

The first of these elements is the col element. The col element is a way to group columns to specify attributes or apply style.

The colspan attribute, which defines how many columns the col element will span.

Example 4-14 demonstrates the use of the col element with a span attribute of 2. You'll notice I've also added the width attribute, defining a width, and that the col element requires a trailing slash: <col />.

Example 4-14. Using the col element to apply attributes to a number of columns

<table width="90%" border="1" cellspacing="5" cellpadding="5" summary="This table explores
 column grouping">
<caption>Column Grouping</caption>
<col span="2" width="100" />
<tr>
<th>Table Head</th>
<th>Table Head</th>
<th>Table Head</th>
</tr>

<tr>
<td>data</td>
<td>data</td>
<td>data</td>
</tr>

<tr>
<td>data</td>
<td>data</td>
<td>data</td>
</tr>
</table>

Figure 4-15 demonstrates how the first two columns are now grouped. The width I've defined in the col element of 100 pixels applies to both columns in the spanned group.

You can add other presentational attributes, too, including the align and valign attributes:

<col span="2" width="100" align="right" valign="bottom" />

This markup creates the results found in Figure 4-16.

group than it is in the right column, which isn't part of the group.