What are the selector styles?

Selector styles include element selector, class selector, ID selector, attribute selector, pseudo-class selector, pseudo-element selector, descendant selector, child element selector, adjacent sibling selector and universal sibling selectors etc. Detailed introduction: 1. Element selector, select elements through the tag name of HTML elements, you can use the element selector to apply the same style to all elements of the same type; 2. Class selector, select elements through the class attribute of the element, use " ." symbol to represent a class selector; you can use a class selector to group a group with the same characteristics, etc.

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

Selector style refers to using selectors in CSS to select elements and apply styles to these elements. CSS provides a variety of selector styles. The following are some commonly used selector styles:

1. Element Selector (Element Selector): Select elements through the tag names of HTML elements. For example, the p selector selects all paragraph elements. You can use element selectors to apply the same style to all elements of the same type.

2. Class Selector: Select elements through their class attributes. Use the "." symbol to represent class selectors. For example, .red will select elements with the class attribute "red". You can use class selectors to apply the same style to a group of elements with the same characteristics.

3. ID Selector: Select elements through their id attribute. Use the "#" symbol to represent ID selectors. For example, #header selects elements with the id attribute "header". ID selectors have higher priority and can be used to apply specific styles to specific elements.

4. Attribute Selector: Select elements through their attributes. For example, [type="text"] will select all elements whose type attribute value is "text". Attribute selectors can select elements based on their attribute values ​​and apply styles to them.

5. Pseudo-class Selector: Select elements through their special status. Pseudo-class selectors start with ":". For example, a:hover selects the mouse-over state of a link. Pseudo-class selectors can apply styles to specific states of elements, such as hover, click, etc.

6. Pseudo-element Selector: Select a specific part of the element. Pseudo-element selectors start with "::". For example, ::before selects content inserted before the element. Pseudo-element selectors can be used to apply styles to specific parts of an element, such as inserting content before the element.

7. Descendant Selector: Select elements through their descendant relationship. Use spaces to indicate descendant selectors. For example, div p will select all paragraph elements inside the div element. Descendant selectors select elements that are descendants of an element and apply styles to them.

8. Child Selector: Select elements through their direct child element relationship. Use the ">" symbol to represent child element selectors. For example, ul > li will select the direct child element li under the ul element. Child selectors select the direct children of an element and apply styles to them.

9. Adjacent Sibling Selector: Selects the sibling element immediately following the specified element. Use the " " notation to represent adjacent sibling selectors. For example, h1 p will select the paragraph element immediately following the h1 element. The neighbor selector selects an element's neighbor elements and applies styles to them.

10. General Sibling Selector: Selects all sibling elements that have the same parent element as the specified element and are behind the specified element. Use the "~" symbol to represent a universal sibling selector. For example, h1 ~ p will select all paragraph elements that have the same parent element as the h1 element and are behind the h1 element. The universal sibling selector selects an element's universal siblings and applies styles to them.

In addition to the common selector styles listed above, there are some other selector styles, such as parent element selector, space selector, etc. Different selector styles can be combined for more precise element selection and style application.

It should be noted that the more specific the selection range of the selector style, the higher the priority. When writing CSS styles, you should choose the appropriate selector style according to specific needs to ensure that the style can be accurately applied to the target element. At the same time, you should also pay attention to the performance of the selector style to avoid rendering performance degradation caused by overly complex selectors.

To summarize, CSS provides a variety of selector styles, including element selectors, class selectors, ID selectors, attribute selectors, pseudo-class selectors, pseudo-element selectors, descendant selectors, and child selectors. Element selectors, adjacent sibling selectors, universal sibling selectors, etc. By rationally using these selector styles, you can accurately select elements and apply styles to achieve rich and diverse page layouts and effects.

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