Resources | Subject Notes | Information Communication Technology ICT
In web development, both styles and classes are fundamental concepts for controlling the visual presentation of a website. Understanding their characteristics and the differences between them is crucial for creating well-structured and maintainable web pages.
A class is a naming convention used in HTML to group elements that share common characteristics or require the same styling. Classes are defined within the HTML code using the class
attribute.
Characteristics of a Class:
Example:
This paragraph will be highlighted.
Styles define the visual appearance of HTML elements. Styles can be applied in three main ways:
style
attribute.
tag in the
section of the HTML document..css
file and linked to the HTML document using the
tag in the
section. This is the recommended approach for larger websites.Characteristics of a Style:
The key difference lies in their purpose and application:
Feature | Class | Style |
---|---|---|
Purpose | Groups elements for consistent styling. | Defines the visual appearance of elements. |
Application | Applied to HTML elements using the class attribute. |
Defined using the style attribute (inline), tag (internal), or a .css file (external). |
Reusability | Highly reusable across multiple elements. | Can be reused (especially with external stylesheets) but is primarily applied to specific elements. |
Here's an example demonstrating how to use a class to group elements and then apply styles to that class:
HTML:
<h2 class="important">Main Heading</h2>
<p class="important">This is an important paragraph.</p>
<ul>
<li class="important">Item 1</li>
<li class="important">Item 2</li>
</ul>
CSS (in an external .css file):
.important {
color: blue;
font-weight: bold;
}
Classes and styles are essential tools for controlling the visual presentation of websites. Understanding their characteristics and the distinction between them allows for the creation of well-organized, consistent, and maintainable web pages. Using classes effectively promotes reusability and simplifies the process of updating the website's appearance.