Do not repeat css

CSS (Cascading Style Sheets) can be said to be an important part of modern web design. It can make the layout of web pages achieve better results and make the user interface more beautiful and easier to use. However, with the continuous increase and complexity of web pages, the scale of CSS is also getting larger and larger. There are many repeated style codes in many projects, resulting in CSS files that are too large, inefficient, and difficult to maintain. In order to solve this problem, not repeating CSS has become an important measure for CSS optimization.

So what is non-repeating CSS? Not repeating CSS means extracting the same CSS attribute styles, reducing the duplication of CSS code, and optimizing CSS file size and efficiency. This can reduce the loading time of web pages, accelerate access speed, and improve development efficiency and maintenance costs.

1. CSS duplicate code problem

In many projects, CSS files often contain a large amount of duplicate code. These repeated codes will not only cause the CSS file to be too large, but also seriously affect the performance of the web page. The specific performance is as follows:

1. Excessive code will increase the download time of the website, reduce the speed of the website, and lead to poor user access experience.

2. When changing the style of a web page or adding a new style, you need to edit the same style multiple times in the code, which increases the cost of development and maintenance.

3. Duplicate code will also affect the readability and maintainability of the code, increase the difficulty of the code, and make the code difficult to maintain and iterate.

2. Optimization plan for non-duplicated CSS

To solve this problem, the optimization plan for non-duplicated CSS is to extract the same CSS attribute styles to improve the reusability of the code.

1. Code reuse based on CSS preprocessor

The CSS preprocessor is a tool that can compile CSS code into ordinary CSS. It provides more syntax, functions and Variables to write cleaner CSS code. Variables, functions, and mixins in CSS preprocessors can improve the reusability of CSS and reduce redundancy and duplication of style code.

Among them, variables can be used to store values ​​that are often used in styles such as color values, fonts, sizes, etc., to facilitate use in subsequent codes; functions can be used in scenarios that require complex calculations, value conversion, etc. , concise and efficient; hybrid can encapsulate a set of CSS properties into a CSS block module to reduce code reuse. Through these means, CSS code can be made more concise, easier to maintain, improve reusability, and avoid code duplication.

2. Writing method based on BEM (block element modifier)

BEM is a front-end design style. In the idea of ​​BEM, we divide the UI interface into blocks (Blocks) and elements. (Element) and modifier (Modifier). It makes the structure of the web page clearer and reduces the duplication of styles. Specifically, blocks define independent elements, which are independent parts of the block, and modifiers limit the styles of these elements.

BEM's writing method pays special attention to structure and semantics. First determine the names of the page's blocks (Blocks), elements (Elements), and modifiers (Modifier) ​​from the HTML structure, and then use these names in the CSS style Make settings. This can not only avoid the reuse of CSS, but also make the CSS code clear and readable, which facilitates later maintenance.

3. Summary

Not repeating CSS is something we need to pay attention to during development. This can optimize the scale of CSS, improve web page loading speed, and reduce development and maintenance costs. During the development process, we can use CSS preprocessors and BEM writing methods to improve the reusability of CSS code and avoid code duplication. At the same time, we should also pay attention to the readability and maintainability of the code to make the code clearer and facilitate later maintenance and updates.

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