Summary of the use of three JS loading methods

This time I will bring you a summary of the use of the three loading methods of JS. What are the precautions when using the three loading methods of JS. The following is a practical case, let's take a look.

1: Synchronous loading

The most commonly used method.

<script src="http://yourdomain.com/script.js"></script>

Synchronous mode, also known as blocking mode , will prevent the browser from subsequent processing and stop subsequent parsing. Only when the current loading is completed, the next step can be performed. Therefore, synchronous execution is safe by default. But if there are actions such as outputting document content, modifying DOM, redirecting, etc. in js, it will cause page congestion. Therefore, it is generally recommended to place the