Beginning iOS Game Center and Game Kit: For iPhone, iPad, and iPod touch

Working with Players

At the heart of the Game Center it is a social service, and as such, it revolves around players. You need to be aware of three properties associated with a GKPlayer object. The isFriend property is a Boolean that returns whether the player is a friend of the current local player. The other two properties handle the name of the player, playerID, and alias. The playerID is static and will always point to the same player. The playerID string should never be shown to the user in your app. The alias, on the other hand, is dynamic and can be changed by the user at any time. It should never be used to test the identity of a user, but it should be the only string used to identify the player to your app's user.

CAUTION: Do not make ...