Does ipod remember passcode when passcode is turned off?

If my son set a passcode on his ipod 5 touch and then turned the passcode off, does the ipod remember that passcode when the passcode is turned on again or does he start over with no passcode? One of his friends set a passcode on his ipod. The friend turned the passcode off, but neither of us know what the passcode was that the friend set. I'm afraid one of his friends is going to mess with it and it's going to reactivate that passcode that we don't know.