How to clear browser cache in javascript client

In the daily development process, we often encounter browser cache problems. When our website is updated, but the client still displays the old version of the content, we need to clear the browser cache.

Here, we will introduce a method to clear the browser cache, which is to use JavaScript to clear it on the client side.

1. The principle of caching

Before understanding how to clear the browser cache, you need to first understand the principle of the browser cache. When we visit a website, on the first request, the browser will download the website's resources locally and save them in the cache. In this way, the next time you visit the website, the browser will read the resources directly from the cache without requesting the server again.

The advantage of this is that it can speed up website access and reduce network transmission overhead. However, when the website is updated, the client cannot see the latest content in time, so the browser cache needs to be cleared.

2. How to clear the browser cache

1. Use the meta tag to clear it

In the head tag of the web page, add the following code Clear browser cache:

<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="Pragma" content="no-cache" />

The function of this code is to tell the browser not to cache the content of this page. The disadvantage of this method is that this code needs to be added to the head tag of each page, which is a tedious task for large websites.

2. Use JavaScript to clear

In JavaScript, we can clear the browser cache by changing the href attribute of the location object. The specific code is as follows:

location.href = location.href + '?' + Math.random();

The function of this code is to add a random number after the current URL, making the browser think that this is a new URL, thereby re-requesting the resource to clear the cache.

In addition, we can also use the localStorage object to clear the browser cache. The specific code is as follows:

localStorage.clear();

The function of this code is to clear all data in the localStorage object, including the cache information stored in it.

3. Notes

When using the above method to clear the browser cache, you need to pay attention to the following points:

1. It needs to be cleared after the website is updated. If you clear the cache when the website has not been updated, it will cause the client to re-request resources, but the old version of the content will still be displayed.
2. If the website has a lot of resources, reloading will take a long time. To improve efficiency, you can clear cache only for pages that reference specific resources.
3. The caching mechanism varies from browser to browser. Different browsers have different cache strategies, and you need to test the performance of different browsers when clearing cache.

4. Summary

Clearing the browser cache is a problem often encountered in daily development. Although browser cache can speed up website access, it can also hinder website updates. Using JavaScript to clear the browser cache on the client is a simple and effective method, but you need to pay attention to the above points when using it. We hope this article can help readers better understand the principles of browser cache and master the method of clearing browser cache.

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