The class attribute assigns one or more classnames to the <section> tag.
Classnames are defined in a stylesheet or in a local <style> element.
Classes, i.e. classnames, are used to style elements.
A class attribute styling a <section> element.
The Night Watch (Dutch: De Nachtwacht), is a 1642 painting by Rembrandt van Rijn. It is in the collection of the Amsterdam Museum but is prominently displayed in the Rijksmuseum (State Museum) as the best-known painting in its collection. The Night Watch is the most famous Dutch Golden Age painting.
<style>
.section-class {
background: moccasin;
padding: 20px;
width: 400px;
line-height: 1.7em;
}
</style>
<section class="section-class">
<h2>The Night Watch</h2>
<p>The Night Watch (Dutch: De Nachtwacht), is a 1642
painting by Rembrandt van Rijn. It is in the collection
of the Amsterdam Museum but is prominently displayed
in the Rijksmuseum (State Museum) as the best-known
painting in its collection. The Night Watch is
the most famous Dutch Golden Age painting.
</p>
</section>
Classes (i.e. classnames) are used for styling the section 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.
<section class="classnames">
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
A class attribute styling a <section> element.
Clicking the button toggles a classname that adds a rounded border to the section.
The Night Watch (Dutch: De Nachtwacht), is a 1642 painting by Rembrandt van Rijn. It is in the collection of the Amsterdam Museum but is prominently displayed in the Rijksmuseum (State Museum) as the best-known painting in its collection. The Night Watch is the most famous Dutch Golden Age painting.
<style>
.section-bg {
background: moccasin;
padding: 20px;
width: 400px;
line-height: 1.7em;
}
.section-border { border-radius: 50px; }
</style>
<section id="mysection" class="section-bg">
<h2>The Night Watch</h2>
<p>The Night Watch (Dutch: De Nachtwacht), is a 1642
painting by Rembrandt van Rijn. It is in the collection
of the Amsterdam Museum but is prominently displayed
in the Rijksmuseum (State Museum) as the best-known
painting in its collection. The Night Watch is
the most famous Dutch Golden Age painting.
</p>
</section>
<br />
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let element = document.getElementById("mysection");
element.classList.toggle("section-border");
}
</script>
Two CSS classes are defined in the <style> element.
The class attribute in <section> assigns one classname.
Repeatedly clicking the button toggles another class, toggling the rounded border of the section.
Here is when class support started for each browser:
 Chrome
|
6.0 | Sep 2010 |
 Firefox
|
4.0 | Mar 2011 |
 IE/Edge
|
9.0 | Mar 2011 |
 Opera
|
11.1 | Mar 2011 |
 Safari
|
5.0 | Jun 2010 |
Back to <section>
