An id on a <col> tag assigns an identifier to the col element.
The identifier must be unique across the page.
And id attribute on 2 <col> elements.
| 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; }
.mintcream { background: mintcream; }
</style>
<table class="tb">
<colgroup>
<col id="col1" class="mintcream">
<col id="col3" span="3">
</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 <col> element.
The id allows JavaScript to easily access the <col> 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.
<col 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 <col> tag with a unique id.
Clicking the button toggles its background color.
| Id | First Name | Last Name | Country |
|---|---|---|---|
| ART-303 | Vincent | Van Gogh | Netherlands |
| ART-877 | Paul | Cézanne | France |
<style>
table.tbl { width:100%; border-collapse: collapse; }
.tbl th, .tbl td { padding:3px; border: 1px solid #777; }
.col-mint { background: mintcream; }
.col-turq { background: paleturquoise; }
</style>
<table class="tbl">
<colgroup>
<col id="mycol" class="col-mint">
<col span="3">
</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="toggle();">Toggle background</button>
<script>
let toggle = () => {
let col = document.getElementById("mycol");
col.classList.toggle("col-turq");
}
</script>
The id attribute assigns a unique identifier to the col.
Clicking the button calls JavaScript which locates the col using the id.
It then changes the column background color by chaging the classname.
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 <col>
