What are the front-end selectors?

Front-end selectors include element selectors, class selectors, ID selectors, attribute selectors, descendant selectors, child element selectors, pseudo-class selectors, pseudo-element selectors, etc. Detailed introduction: 1. The element selector is the most basic selector. It selects elements through the tag name of HTML elements; 2. The class selector selects elements based on the class attribute of the element. Use the ".classname" selector. You can select elements with specific class names; 3. ID selector selects elements based on their id attribute, etc.

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

In front-end development, a selector is a tool for selecting HTML elements. It can help developers select and operate elements on the page based on specific conditions. In CSS and JavaScript, there are a variety of selectors available, and below I will introduce some common front-end selectors.

1. Element Selector: The element selector is the most basic selector, which selects elements through the tag name of HTML elements. For example, using the `p` selector selects all paragraph elements.

2. Class Selector: The class selector selects elements based on their class attribute. Use the `.classname` selector to select elements with a specific class name. For example, using the `.red` selector selects all elements with `class="red"`.

3. ID Selector: The ID selector selects elements based on their id attribute. Use the `#idname` selector to select elements with a specific id. For example, use the `#header` selector to select the element with the id `"header"`.

4. Attribute Selector: The attribute selector selects elements based on their attribute values. For example, use the `[attribute=value]` selector to select elements with a specific attribute value. For example, using the `[type="text"]` selector selects all elements whose type attribute value is "text".

5. Descendant Selector: The descendant selector is used to select the descendant elements of an element. Use a space to separate two selectors to select descendant elements of the first selector. For example, using the `div p` selector selects all `p` elements within a `div` element.

6. Child Selector: The child selector is used to select the direct child elements of an element. Use `>` to separate two selectors, indicating that the direct child elements of the first selector are selected. For example, using the `ul > li` selector selects all `li` elements that are direct children of the `ul` element.

7. Pseudo-class Selector: Pseudo-class selector is used to select a specific state or position of an element. For example, use the `:hover` selector to select the mouse-over state of an element, and use the `:nth-child(n)` selector to select the nth child element of an element.

8. Pseudo-element Selector: Pseudo-element selector is used to select a specific part of an element. For example, use the `::before` selector to select content inserted before an element.

These are some common front-end selectors that can select and operate elements on the page according to different needs. It should be noted that the use of selectors can achieve more complex selection effects through combination and nesting.

In actual development, the selection and use of selectors should be determined based on specific needs and HTML structure. Flexible use of these selectors can help developers operate and style page elements more conveniently and improve development efficiency.

To summarize, common front-end selectors include element selectors, class selectors, ID selectors, attribute selectors, descendant selectors, child element selectors, pseudo-class selectors and pseudo-element selectors. They can select and operate elements on the page based on their tag name, class name, id, attributes, status and other conditions. I hope the above answer is helpful to you, if you have any other questions, please feel free to let me know.

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