Class vs. ID Selectors in CSS: When Should I Use Each?

Class vs. ID Selectors in CSS

When defining styles for HTML elements, CSS employs two types of selectors: class and ID. Each type serves a distinct purpose and exhibits different semantics.

Class Selectors (.)

Class selectors are used to target multiple elements that share a specific class attribute. For instance, .container would match all elements with the class attribute set to "container." This allows for applying the same styles to a group of related elements.

ID Selectors (#)

In contrast, ID selectors are utilized to target a single unique element with a specific ID attribute. For example, #header would exclusively select the element with the ID attribute value "header." ID selectors are ideal for targeting elements that appear only once within a document.

Usage Scenarios

• Class Selectors: Styling elements that repeat across the page, such as headings, paragraphs, links, etc.
• ID Selectors: Styling layout components that appear only once, such as header, sidebar, footer, etc.

Specificity

ID selectors have higher specificity than class selectors. This means that if conflicting styles are applied to the same element using both ID and class selectors, the ID selector styles will override the class selector styles.

Additional Resources

To delve deeper into CSS selectors, consider the following resources:

• [Selectutorial](https://www.w3.org/Style/Examples/007/selector.en.html)
• [CSS Specificity](https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity)

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