The class attribute assigns one or more classnames to the <col> tag.
Classnames are defined in a stylesheet or in a local <style> element.
Classes, i.e. classnames, are used to style the col element.
A class attribute styling a <dd> element.
<style>
.dd-italic {font-style: italic;}
</style>
<dl>
<dt>Kunstmuseum</dt>
<dd class="dd-italic">Basel, Switzerland</dd>
<dt>National Gallery of Art</dt>
<dd class="dd-italic">Washington DC, USA</dd>
<dt>Musée d'Orsay</dt>
<dd class="dd-italic">Paris, France</dd>
</dl>
Classes (i.e. classnames) are used for styling the col element.
Multiple classnames are separated by a space.
JavaScript uses classes to access elements by classname.
Tip: class is a global attribute that can be applied to any HTML element.
<dd class="classnames" >
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
A class attribute styling a <dd> element. Clicking the button toggles the background color for all <dd> items.
<style>
.dd-italic { font-style:italic; }
.dd-moccasin { background-color:moccasin; }
</style>
<dl>
<dt>1. Kunstmuseum</dt>
<dd class="dd-italic">Basel, Switzerland</dd>
<dt>2. National Gallery of Art</dt>
<dd class="dd-italic">Washington DC, USA</dd>
<dt>3. Musée d'Orsay</dt>
<dd class="dd-italic">Paris, France</dd>
</dl>
<br/>
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let elements = document.getElementsByClassName("dd-italic");
[].forEach.call(elements, element => element.classList.toggle("dd-moccasin"));
}
</script>
Two CSS classes are defined in the <style> element.
All <dd> elements are assigned with one classname.
Clicking the button retrieves all <dd> elements using that classname.
JavaScript then iterates over the elements and toggles another classname changing the background color.
Here is when class 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 <dd>
