Do Something When A New Customer Registers Or When A New Order Is Placed

Okay guys back to this question, how do I get the newly inserted user ID in the "update_user_pre" function??

You cannot do it, because the ID is received after this hook

Okay, which hook I should use then. I just need new customer registrations data with their IDs. Thanks

Use the update_profile hook in same function. it contains the $action parameter which indicates if the profile was added or updated

It works :) Thank you very much

You are welcome! :)