What happens is that, if $_POST['userid'] is set then $userid should get it's value. But if its not, $userid should get the value 43, and the $error variable should be set to true. And it sure works. But I don't really get what happens there. I just tried the $error = true | 43 by a coincidence, and it works, but I'm not sure if it's really the right way of doing it? Is this really correct syntax?
And if it is good syntax... Is it any way of making this even shorter? for example so I don't have to write $_POST['userid'] two times? So I could replace it with $1 or something like that.