The class attribute assigns one or more classnames to the <del> tag.
Classnames are defined in a stylesheet or in a local <style> element.
Classes, i.e. classnames, are used for styling the del element.
A class attribute styling a <details> element.
Sunflowers
Starry Night
Self Portrait
<style>
.bg-blue { background-color:aliceblue;padding: 10px; }
</style>
<details class="bg-blue">
<summary>Van Gogh's Paintings</summary>
<p>Sunflowers</p>
<p>Starry Night</p>
<p>Self Portrait</p>
</details>
Classes (i.e. classnames) are used for styling the del 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.
<details class="classnames" >
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
A class attribute styling a <details> element.
Clicking the button toggles a classname that changes the background color.
Sunflowers
Starry Night
Self Portrait
<style>
.bg-blue { background-color:aliceblue;padding: 10px; }
.bg-turq { background-color:paleturquoise; }
</style>
<details class="bg-blue" id="mydetails">
<summary>Van Gogh's Paintings</summary>
<p>Sunflowers</p>
<p>Starry Night</p>
<p>Self Portrait</p>
</details>
<br/>
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let element = document.getElementById("mydetails");
element.classList.toggle("bg-turq");
}
</script>
Two CSS classes are defined in the <style> element.
The class attribute on the <details> element assigns one classname.
Repeatedly clicking the button toggles another class, changing the background color.
Here is when class support started for each browser:
 Chrome
|
12.0 | Jun 2011 |
 Firefox
|
49.0 | Sep 2016 |
 IE/Edge
|
Not supported | |
 Opera
|
15.0 | Jul 2015 |
 Safari
|
6.0 | Jul 2012 |
Back to <details>
