How to determine the true user id on Facebook?

Question

PHP

Hello. In the facebook application, it gives out a User Id, not the one that is shown in my profile. They are different, how can I find out the original id knowing only the Id that is issued in the application and vice versa?

Answer 1

No way. Recently, they have a strict policy on this matter. When installing an application, the network returns a so-called app_user_id. On it you can go to the true profile, but only go.
To find out the usual user_id, you can open the profile page with curl and get it from there.