An id on a <colgroup> tag assigns an identifier to the element.
The identifier must be unique across the page.
An id attribute on a <colgroup>.
| Id | First Name | Last Name | Country |
|---|---|---|---|
| ART-303 | Vincent | Van Gogh | Netherlands |
| ART-877 | Paul | Cézanne | France |
<style>
table.tb { width:100%; border-collapse: collapse; }
.tb th, .tb td { padding:3px; border: 1px solid #777; }
</style>
<table class="tb">
<colgroup id="table-colgroup">
<col style="background:aliceblue;" />
</colgroup>
<tr>
<th>Id</th>
<th>First Name</th>
<th>Last Name</th>
<th>Country</th>
</tr>
<tr>
<td>ART-303</td>
<td>Vincent</td>
<td>Van Gogh</td>
<td>Netherlands</td>
</tr>
<tr>
<td>ART-877</td>
<td>Paul</td>
<td>Cézanne</td>
<td>France</td>
</tr>
</table>
The id attribute assigns an identifier to the <colgroup> element.
The id allows JavaScript to easily access the <colgroup> element.
It is also used to point to a specific id selector in a style sheet.
Tip: id is a global attribute that can be applied to any HTML element.
<colgroup id="identifier" />
| Value | Description |
|---|---|
| identifier | A unique alphanumeric string. The id value must begin with a letter ([aside-Zaside-z]) and may be followed by any number of letters, digits ([0-9]), hyphens (-), underscores (_), colons (:), and periods (.). |
A <colgroup> tag with a unique id.
Clicking the button displays the span value of the column group.
| Id | First Name | Last Name | Country |
|---|---|---|---|
| ART-303 | Vincent | Van Gogh | Netherlands |
| ART-877 | Paul | Cézanne | France |
<style>
table.tb { width:100%; border-collapse: collapse; }
.tb th, .tb td { padding:3px; border: 1px solid #777; }
</style>
<table class="tb">
<colgroup id="mycolgroup"
span="3"
style="background:aliceblue;">
</colgroup>
<tr>
<th>Id</th>
<th>First Name</th>
<th>Last Name</th>
<th>Country</th>
</tr>
<tr>
<td>ART-303</td>
<td>Vincent</td>
<td>Van Gogh</td>
<td>Netherlands</td>
</tr>
<tr>
<td>ART-877</td>
<td>Paul</td>
<td>Cézanne</td>
<td>France</td>
</tr>
</table>
<br/>
<button onclick="show();">Show colgroup span</button>
<script>
let show = () => {
let element = document.getElementById("mycolgroup");
alert("Colgroup span = " + element.span);
}
</script>
The id attribute assigns a unique identifier to the colgroup.
Clicking the button calls JavaScript which locates the colgroup using the id.
It extracts and displays the span attribute value.
Here is when id support started for each browser:
 Chrome
|
1.0 | Sep 2008 |
 Firefox
|
1.0 | Sep 2002 |
 IE/Edge
|
1.0 | Aug 1995 |
 Opera
|
1.0 | Jan 2006 |
 Safari
|
1.0 | Jan 2003 |
Back to <colgroup>
