When using jQuery, I found the following error:

Uncaught ReferenceError: $ is not defined (anonymous function)

The reason for this error:

1. The path of the jQuery library file is incorrect. Checking whether the file path is correct can usually solve the error.

2. If the path of the library file is correct, the order of loading the jQuery library file in the html may be wrong. If the jQuery library file is loaded in the first position, the error can be solved.