What to do if javascript is not displayed in the browser

JavaScript is an indispensable technology in modern web development. You can do many interesting things in web pages, such as dynamically changing page content, responding to user events, interacting with data from the server, and so on. However, sometimes we encounter such a problem: when running JavaScript code in the browser, nothing happens at all, not even an error message. How should we solve this situation?

The following are some common situations and solutions.

1. JavaScript files must be introduced in HTML files
   When writing HTML files, if you want to use JavaScript scripts, you must use the <script> tag in HTML to introduce JavaScript files, for example: </script>

  <title>测试</title>


  <script></script>

In the above code, the test.js file is introduced through the src attribute of the <script> tag. If the file is not included correctly, JavaScript will not work. </script>

2. Check whether the JavaScript file path is correct
When introducing JavaScript files, you should also pay attention to the file path. If the file path is written incorrectly, JavaScript will not take effect. Generally speaking, it is best to use relative paths to introduce files, so as to avoid path inconsistencies on different machines and different servers.

3. Check whether the JavaScript code is correct
   JavaScript code has certain grammatical rules. If there is a grammatical error in the code, JavaScript will not be executed in the browser. During the development process, check for grammatical errors frequently and make timely modifications.
4. Confirm that the browser supports JavaScript
   JavaScript is a browser-side technology, so different browsers have different levels of support for JavaScript. If some new JavaScript features are used and the user's browser does not support these features, the JavaScript code will not take effect. At this time, we can use polyfill or feature checking to solve the problem.
5. Check browser security settings
   Sometimes, browser security settings can also affect the operation of JavaScript. If JavaScript is disabled by the browser, it will not take effect. We need to check the settings in the browser to confirm that JavaScript has permission to run.

To sum up, there may be many reasons why JavaScript cannot take effect in the browser, and we need to check them one by one. Only when the problem is identified can corrective measures be taken. At the same time, in daily development, you should also pay attention to writing high-quality JavaScript code to avoid some common errors and problems. In this way, we can better utilize JavaScript technology to develop richer and more interactive web applications.

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