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What is the difference between CSS class selector and ID selector

Shulou Source: shulou.com Published: 2022-06-01 04:24:53 09月22日 Update

This article mainly introduces the CSS class selector and ID selector what is the difference between the relevant knowledge, the content is detailed and easy to understand, simple and fast operation, has a certain reference value, I believe you read the difference between CSS class selector and ID selector is what the article will have a harvest, let's take a look at it.

Difference 1: can only be used once in a document

Unlike classes, the ID selector is used once and only once in an HTML document.

Difference 2: cannot use ID word list

Unlike class selectors, ID selectors cannot be used together because the ID property does not allow a list of words separated by spaces.

Distinguishing 3:ID can have more meaning.

Similar to classes, ID can be selected independently of the element. In some cases, you know that a particular ID value will appear in the document, but you don't know which element it will appear on, so you want to declare a separate ID selector. For example, you might know that there will be an element with an ID value of mostImportant in a given document. You don't know whether the most important thing is a paragraph, a phrase, a list item, or a section heading. All you know is that every document has the most important content, which can be in any element, and there can only be one. In this case, you can write the following rules:

# mostImportant {color:red; background:yellow;}

This rule matches the following elements (these elements cannot appear in the same document at the same time, because they all have the same ID value):

This is important!This is important!This is important! This is the end of the article on "what's the difference between CSS class selectors and ID selectors". Thank you for reading! I believe you all have a certain understanding of the knowledge of "what is the difference between CSS class selector and ID selector". If you want to learn more, you are welcome to follow the industry information channel.

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