How many types of css selectors are there?

CSS selector is a pattern used to select an element in an HTML or XML document. It allows developers to obtain elements in the page through selectors such as class name, ID, tag name, etc., thereby changing the style, behavior and content of the element. In CSS, selectors are one of the most critical concepts and the core of CSS. This article will introduce the types of CSS selectors in detail.

1. Tag Selector

The most basic CSS selector is the tag selector, which selects elements based on HTML tags. For example, the following CSS selector will select all paragraphs in HTML:

p {
  color: red;
}

2. ID selector

The ID selector selects elements by their unique ID. . In HTML, the ID of each element should be unique. For example, the following CSS selector will select the element with the ID "my-element":

#my-element {
  background-color: yellow;
}

3. Class selector

The class selector allows us to base the class of an element on it. attributes to select elements. In HTML, multiple elements can use the same class name. For example, the following CSS selector will select all elements in HTML with the class "my-class":

.my-class {
  font-size: 16px;
}

4. Adjacent Sibling Selector

Adjacent Sibling A selector selects elements based on the sibling elements that follow the specified element. For example, the following CSS selector will select all p elements immediately following the h1 element:

h1 + p {
  color: blue;
}

5. Child element selector

Child element selector selects the specified element direct child element. For example, the following CSS selector will select all direct child elements li in the ul element:

ul > li {
  list-style: none;
}

6. Descendant selector

The descendant selector will select all elements under the specified element. All descendant elements. For example, the following CSS selector will select all li elements under the div element:

div li {
  color: purple;
}

7. Wildcard selector

The wildcard selector matches all elements in the HTML document. For example, the following CSS selector will select every element in HTML:

* {
  margin: 0;
  padding: 0;
}

8. Attribute selector

Attribute selector selects elements by their attribute values. For example, the following CSS selector will select all elements whose class attribute contains "my":

[class*="my"] {
  background-color: green;
}

Summary:

The CSS selector can be based on tags, classes, IDs, and attributes in HTML documents Characteristics to select elements and modify their styles. This article introduces 8 commonly used CSS selectors that can be used to solve common styling problems. It is important to note that using CSS selectors correctly can make developers' CSS code more concise and clear.

The above is the detailed content of How many types of css selectors are there?. For more information, please follow other related articles on the PHP Chinese website!