The class attribute assigns one or more classnames to the <header> 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 <header> element.
<style>
.header-dark {background:#1f2936; color:white; padding:10px;}
</style>
<header class="header-dark">
Company logo here...
</header>
Classes (i.e. classnames) are used for styling the header 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.
<header class="classnames">
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
A class attribute styling a <header> element.
Clicking the button toggles a classname that changes the background and text colors.
<style>
.header-dark {background:#1f2936; color:white; padding:10px;}
.header-indigo {background-color:#c6d2fe; color:black;}
</style>
<header id="myheader" class="header-dark">
Company logo here...
</header>
<br/>
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let element = document.getElementById("myheader");
element.classList.toggle("header-indigo");
}
</script>
Two CSS classes are defined in the <style> element.
The class attribute in <header> assigns one classname.
Repeatedly clicking the button toggles another class, changing the background and text color of the <header>.
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 <header>
