The class attribute assigns one or more classnames to the <td> 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 <td> elements.
| First name | Last name |
|---|---|
| Denice | Hobermann |
| Paulo | Cornell |
<style>
table.tb { width:300px; border-collapse: collapse; }
.tb th, .tb td { border: solid 1px #777; padding: 5px; }
.tb th { background: #3630a3; color: white; text-align:left; }
.tcell { background: #f6f8ff; }
</style>
<table class="tb">
<tr>
<th>First name</th>
<th>Last name</th>
</tr>
<tr>
<td class="tcell">Denice</td>
<td class="tcell">Hobermann</td>
</tr>
<tr>
<td class="tcell">Paulo</td>
<td class="tcell">Cornell</td>
</tr>
</table>
Classes (i.e. classnames) are used for styling the td 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.
<td class="classnames">
| Value | Description |
|---|---|
| classnames | One or more space-separated class names. |
A class attribute styling <td> elements.
Clicking the button toggles a classname that changes the background color of the table cells.
| First name | Last name |
|---|---|
| Denice | Hobermann |
| Paulo | Cornell |
<style>
table.tb { width:300px; border-collapse: collapse; }
.tb th, .tb td { border: solid 1px #777; padding: 5px; }
.tb th { background: #3630a3; color: white; text-align:left; }
.tcell { background: #f6f8ff; }
.tlite { background: #fff; }
</style>
<table class="tb">
<tr>
<th>First name</th>
<th>Last name</th>
</tr>
<tr>
<td class="tcell">Denice</td>
<td class="tcell">Hobermann</td>
</tr>
<tr>
<td class="tcell">Paulo</td>
<td class="tcell">Cornell</td>
</tr>
</table>
<br />
<button onclick="toggle();">Toggle class</button>
<script>
let toggle = () => {
let elements = document.getElementsByClassName("tcell");
[].forEach.call(elements, element => element.classList.toggle("tlite"));
}
</script>
Two CSS classes are defined in the <style> element.
The class attribute in <td> assigns one classname.
Repeatedly clicking the button calls JavaScript which locates all the <td> tags using classnames.
It then toggles the another class, changing the background and text 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 <td>
