HTML TutorialLesson #24

HTML Classes

The HTML `class` attribute is

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

The class attribute is often used to point to a class name in a style sheet. It can also be used by 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:

Example

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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:

Example

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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.


The Syntax For Class

To create a class; write a period (.) character, followed by a class name. Then, define the CSS properties within curly braces {}:

Example

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Multiple Classes

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:

Example

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Different Elements Can Share Same Class

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:

Example

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Use of the class Attribute in JavaScript

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:

Example

Example Code

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<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.


Chapter Summary

  • The HTML class attribute specifies one or more class names for an element
  • Classes are used by CSS and JavaScript to select and access specific elements
  • The class attribute can be used on any HTML element
  • The class name is case sensitive
  • Different HTML elements can point to the same class name
  • JavaScript can access elements with a specific class name with the getElementsByClassName() method

Video: HTML Class


Interactive Code Examples

HTML Example 1

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Interactive runnable HTML example from EA Academy.
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HTML Example 2

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Interactive runnable HTML example from EA Academy.
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HTML Example 3

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Interactive runnable HTML example from EA Academy.
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HTML Example 4

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Interactive runnable HTML example from EA Academy.
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HTML Example 5

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Interactive runnable HTML example from EA Academy.
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HTML Example 6

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HTML tag syntax and structure demonstration.
<script>
function myFunction() {
  var x = document.getElementsByClassName("city");
  for (var i = 0; i < x.length; 
  i++) {
    x[i].style.display = "none";
  }
}
</script>