What is the use of adding question marks and numbers after css and js?

Function: Force the browser to call a new address to prevent caching. Adding question marks and random numbers after css and js will not affect the file call; however, if the number is changed, the browser will read it as a new file and will not read the previous cached file.

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The function of adding question marks and numbers after css and js: mandatory The browser calls the new address to prevent caching.

When the browser requests a website, it will load a variety of resources, such as HTML documents, images, CSS and JS files. For some content that does not change frequently, the browser will save them in local files. The next time you visit the same website, these resources will be directly loaded to speed up access. These files saved by the browser are called caches.

The browser has a caching policy, so you will encounter a problem, that is, it cannot load the latest css and js files in time.

In order to solve this problem, we will add question marks and some random characters after the css and js links.

Similar to css/index2.css?20130201

Theoretically, adding numbers after css or js is useless and will not affect the calling of the file. However, if the number is changed, the browser will read it as a new file and not the previous cached file.

So, adding a number has the same effect as adding a random number after the URL, which is to force the browser to call a new address to prevent caching.

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