The class attribute assigns one or more classnames to the <option> tag.
Classnames are defined in a stylesheet or in a local <style> element.
Classes, i.e. classnames, are used to style elements.
Four <option> element styled with a class attribute.
<style>
.option { background: #dfe7ff; color: #4e46e5;}
</style>
<select>
<option>-- Select country --</option>
<option class="option">United States</option>
<option class="option">United Kingdom</option>
<option class="option">Thailand</option>
<option class="option">India</option>
</select>
Classes (i.e. classnames) are used for styling the option 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.
<option class="classnames">
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
Four <option> element styled with a class attribute.
Clicking the button toggles a classname that changes the option text to bold.
<style>
.option-indigo { background: #dfe7ff; color: #4e46e5;}
.bold { font-weight: bold; }
</style>
<select>
<option>-- Select country --</option>
<option class="option-indigo">United States</option>
<option class="option-indigo">United Kingdom</option>
<option class="option-indigo">Thailand</option>
<option class="option-indigo">India</option>
</select>
<br />
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let elements = document.getElementsByClassName("option-indigo");
[].forEach.call(elements, element => element.classList.toggle("bold"));
}
</script>
Two CSS classes are defined in the <style> element.
Clicking the button locates all the <option> elements one classname.
Javascript then iterates over the elements and toggle the second classname changing the text boldness.
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 <option>
