ViewController.swift

extension ViewController: ASAuthorizationControllerDelegate {
      //1
      func authorizationController(controller: ASAuthorizationController, 
                                   didCompleteWithAuthorization 
                                   authorization: ASAuthorization) {
          //1.1
          if let appleIDCredential = authorization.credential as?  
                  ASAuthorizationAppleIDCredential {
              let userIdentifier = appleIDCredential.user
              let fullName = appleIDCredential.fullName
              let email = appleIDCredential.email
              print("User id is \(userIdentifier) \n 
                    Full Name is \(String(describing: fullName)) \n 
                    Email id is \(String(describing: email))") 
          }
      }
      //2
      func authorizationController(controller: ASAuthorizationController, 
                                   didCompleteWithError error: Error) {
          print(error)
      }
}