Where to put jquery loading

jQuery is a very popular JavaScript library that is widely used in building rich web applications. When using jQuery, consider how to load the library to ensure it is used correctly.

In this article, we will explore jQuery loading best practices and its impact on web page performance and user experience.

1. How to load jQuery

In Web development, there are two methods of loading jQuery: synchronous loading and asynchronous loading.

The synchronous loading method is to embed the jQuery library into the web page code, and load the jQuery library together when the web page is loaded. The disadvantage of this method is that since the JavaScript code needs to be loaded in the main thread, if the jQuery library is too large or the web page itself is too complex, it will cause slow loading speed and slow web page response, giving users a bad experience.

Relatively speaking, the asynchronous loading method is more excellent. It does not block the loading of the Web page, but dynamically loads the jQuery library when needed. The advantage of this method is that it can improve the loading speed of web pages, so that users can get responses faster and improve user experience.

2. Placement of the jQuery library

When loading the jQuery library asynchronously, we also need to consider where to place it. Generally, there are two placement locations: in the head tag or at the very bottom in the body tag.

1. Place the jQuery library in the head tag

The advantage of this approach is that it allows the jQuery library to be loaded as early as possible to ensure that the jQuery library already exists when subsequent code is executed. This is because the execution of JavaScript code occurs sequentially, and if you want to use the functionality of the jQuery library, it must be loaded first.

However, the disadvantage of placing the jQuery library in the head tag is that it will slow down the loading time of the web page. Since web pages are loaded sequentially, if the jQuery library is loaded before the JavaScript code is loaded, the jQuery library will be loaded before the HTML and CSS are read and rendered. This will make the rendering time of the page longer and affect the user experience.

2. Place the jQuery library at the bottom of the body tag

Placing the jQuery library at the bottom of the body tag is to solve the above problem. This way, the loading of the jQuery library can occur after the rest of the web page has loaded. This means that elements such as HTML and CSS have been fully loaded and rendered before the jQuery library is loaded, making the web page feel more responsive to users and improving their experience.

However, this approach may cause problems in some situations. If the JavaScript code takes a lot of time to execute, loading the jQuery library at the very bottom of the body tag may cause dependency issues and error messages when the code runs.

3. Conclusion

In summary, loading the jQuery library asynchronously and placing it at the bottom of the body tag is a best practice, which can render the web page as quickly as possible and improve the user experience. .

In some cases, loading the jQuery library synchronously or placing it in the head tag may follow.

As web developers, we need to choose the best loading method and placement based on specific situations in order to optimize web page performance and improve user satisfaction.

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