HTML tutorial
CSS3 tutorial
Bootstrap tutorial
JavaScript tutorial
JQuery tutorial
AngularJS tutorial
React tutorial
NodeJS tutorial
PHP tutorial
Python tutorial
Python3 tutorial
Django tutorial
Linux tutorial
Docker tutorial
Ruby tutorial
Java tutorial
C tutorial
C ++ tutorial
Perl tutorial
JSP tutorial
Lua tutorial
Scala tutorial
Go tutorial
ASP.NET tutorial
C # tutorial
The HTML class attribute is used to specify a class for an HTML element.Multiple HTML elements can share the same class
The class
attribute is often used to point
to a class name in a style sheet. It can also be used by a JavaScript to access and
manipulate elements with the specific class name.
In the following example we have three <div>
elements
with a class
attribute with the value of
"city". All of the three <div>
elements will be styled equally according to the .city
style definition in the head section:
<!DOCTYPE html>
<html>
<head>
<style>
.city {
background-color: tomato;
color: white;
border: 2px solid black;
margin: 20px;
padding: 20px;
}
</style>
</head>
<body>
<div class="city">
<h2>London</h2>
<p>London is the capital of England.</p>
</div>
<div class="city">
<h2>Paris</h2>
<p>Paris is the capital of France.</p>
</div>
<div class="city">
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan.</p>
</div>
</body>
</html>
In the following example we have two <span>
elements
with a class
attribute with the value of
"note". Both <span>
elements will be styled equally according to the .note
style definition in the head section:
<!DOCTYPE html>
<html>
<head>
<style>
.note {
font-size: 120%;
color: red;
}
</style>
</head>
<body>
<h1>My <span class="note">Important</span> Heading</h1>
<p>This is some <span class="note">important</span> text.</p>
</body>
</html>
Tip: The class
attribute can be used on any HTML element.
Note: The class name is case sensitive!
Tip: You can learn much more about CSS in our CSS Tutorial.
To create a class; write a period (.) character, followed by a class name. Then, define the CSS properties within curly braces {}:
Create a class named "city":
<!DOCTYPE html>
<html>
<head>
<style>
.city {
background-color: tomato;
color: white;
padding: 10px;
}
</style>
</head>
<body>
<h2 class="city">London</h2>
<p>London is the capital of England.</p>
<h2 class="city">Paris</h2>
<p>Paris is the capital of France.</p>
<h2 class="city">Tokyo</h2>
<p>Tokyo is the capital of Japan.</p>
</body>
</html>
HTML elements can belong to more than one class.
To define multiple classes, separate the class names with a space, e.g. <div class="city main">. The element will be styled according to all the classes specified.
In the following example, the first <h2>
element belongs to both the
city
class and also to the main
class,
and will get the CSS styles from both of the classes:
<h2
class="city main">London</h2>
<h2 class="city">Paris</h2>
<h2
class="city">Tokyo</h2>
Different HTML elements can point to the same class name.
In the following example, both <h2>
and <p>
point to the "city" class
and will share the same style:
<h2 class="city">Paris</h2>
<p
class="city">Paris is the capital of France</p>
The class name can also be used by JavaScript to perform certain tasks for specific elements.
JavaScript can access elements with a specific class name with the getElementsByClassName()
method:
Click on a button to hide all elements with the class name "city":
<script>
function myFunction() {
var x = document.getElementsByClassName("city");
for (var i = 0; i < x.length;
i++) {
x[i].style.display = "none";
}
}
</script>
Don't worry if you don't understand the code in the example above.
You will learn more about JavaScript in our HTML JavaScript chapter, or you can study our JavaScript Tutorial.
class
attribute specifies one or
more class names for an elementclass
attribute can be used on any
HTML elementgetElementsByClassName()
methodCreate a class selector named "special".
Add a color property with the value "blue" inside the "special" class.