Small selector problems in jQuery (newcomers will inevitably encounter them)_jquery

Today I followed the jQuery manual and learned about the use of selectors. I was going to try writing a user registration verification. Unexpectedly, a very small problem stumped me before I even started!

Newcomers will inevitably encounter small details. This article is only for self-help:

The test part of the code is as follows:

Copy the code The code is as follows:

< legend>Registration page
Username

Password

Verify password

email