What is the difference between pseudo-elements and pseudo-classes?

The difference between pseudo-element and pseudo-class is: 1. Pseudo-class is a selector used to select a specific state or position of an element, while pseudo-element is used to insert additional elements before or after the content of the element. Content selector; 2. The function of pseudo-class is to change the style of the element according to its state or position, while the function of pseudo-element is to insert additional content before or after the content of the element and modify its style.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

Pseudo elements and pseudo classes are two concepts commonly used in CSS. They are both used to style HTML elements. Although their names are similar, they have clear differences in use and functionality.

First, let’s take a look at pseudo classes. Pseudo-classes are selectors used to select a specific state or position of an element. They start with a colon (:) and are used to apply styles to specific elements. Common pseudo-classes include:hover (mouse hover state), :active (activation state), :visited (visited link), etc. The way to use pseudo-classes is to add a colon and the pseudo-class name after the selector, for example: a:hover, input:disabled, etc.

The purpose of the pseudo-class is to change the style of the element based on its state or position. For example, when the mouse hovers over a link, we can use the :hover pseudo-class to change the link's color or background color. Pseudo-classes can dynamically change styles based on user operations or the state of elements, making the page more interactive and lively.

Next, let’s take a look at pseudo elements. Pseudo-elements are selectors used to insert additional content before or after the content of an element. They start with a double colon (::) and are used to apply styles to specific parts of an element. Common pseudo-elements include ::before (insert content before element content), ::after (insert content after element content), etc. The way to use pseudo-elements is to add double colons and pseudo-element names after the selector, such as: p::before, div::after, etc.

The function of pseudo-element is to insert additional content before or after the content of the element and modify it with style. For example, we can use the ::before pseudo-element to insert an icon or decorative symbol before a paragraph. Pseudo elements can be used to achieve some special effects or decorations to make the page more beautiful and interesting.

To sum up, pseudo-classes and pseudo-elements play different roles in CSS. Pseudo-classes are used to select a specific state or position of an element and change the style according to its state, while pseudo-elements are used to insert additional content before or after the content of the element and modify it with styles. They are all used to enhance the functionality and expressiveness of CSS, allowing us to better control and beautify the style of web pages. .

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