js lazy loading changes the position of JS to speed up web page loading_Basic knowledge

When a website has a lot of js code to be loaded, the location of the js code will affect the loading speed of the web page to a certain extent. In order to make our web page load faster, this article summarizes a few points to pay attention to:
1. Lazy loading js code

Copy code The code is as follows:

< ;script type="text/javascript" src="" id="my">

In this way, js code is loaded through delay, Allow more time for web pages to load!

2. JS final loading solution 1
Insert the following code where JS needs to be inserted:
Program code

Copy code The code is as follows:

LOADING…

Of course, that LOADING... you can change it to a small picture you like. It looks very AJAX effective.
Then insert at the bottom of the page:
Program code

Copy code The code is as follows:

Your JS code is here!> ;
<script>L4EVER.innerHTML=AD_L4EVER.innerHTML;AD_L4EVER.innerHTML=”";</script>

3. Let JS load the second solution lastly
This involves the loading order of the web page. For example, when introducing an external js script file, if it is placed in the head of the html, the js script will be loaded into the page before the page is loaded, and if it is placed in the body, then The javascript code will be run in the order in which the page is loaded from top to bottom~~~ So we can put the files imported from outside the js to the bottom of the page, so that the js will be introduced last, thereby speeding up the page loading speed.