Return False not working inside jQuery.ajax

Question

P.S.: Read \"EDITED on 2019-06-29\":

I have a webform for updating user information, and when he updates his email a verification is performed via

Answer 1

You run async code here. At the moment you are trying to return false, it is far to late. Your function already returned undefined. You need to provide a callback if you want to process the result of your success.