Passing data between view controllers

ok so i need to send data between two different view controllers. what i need is to pass three strings between the two so that the second view controller can submit info to parse which is not happening because when used the variables are all equal to zero.

''' IOS

• (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{

  if ([segue.identifier isEqualToString:@"chief"]) {

  NSString *name = self.name.text;
  
  NSString *password = self.password.text;
  
  NSString *schoolEmail = self.schoolEmail.text;
  
  if ([name length] == 0 || [password length] == 0 || [schoolEmail length] == 0) {
  
      UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Oops!" message:@"Make sure you enter a 
  

username, password, and email address!"delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];

        [alertView show];

    }

    CrewChiefViewController *viewController = (CrewChiefViewController *)segue.destinationViewController;


    viewController.usernameB = name;

    viewController.passwordB = password;

    viewController.emailB = schoolEmail;




}

}

@end '''

i have tested every point possible in this and the variable always has a value. then on the next view controller when it loads there is a value but at the point of create account it is then empty

''' IOS

• (void)viewDidLoad

{ [super viewDidLoad];

if ([self.usernameB length] == 0 || [self.passwordB length] == 0 || [self.emailB length] == 0) {

    UIAlertView *alertView2 = [[UIAlertView alloc] initWithTitle:@"Oops!" message:@"It Has not Worked"delegate:nil 

cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];

    [alertView2 show];

}

}

• (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

[self.phrase resignFirstResponder];

}

• (IBAction)createAccount:(id)sender {

  if ([self.usernameB length] == 0 || [self.passwordB length] == 0 || [self.emailB length] == 0) {

  UIAlertView *alertView2 = [[UIAlertView alloc] initWithTitle:@"Oops!" message:@"It Has not Worked"delegate:nil 
  

cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];

    [alertView2 show];

    NSLog(@"error");
}



PFUser *crewChief = [PFUser user];

crewChief.username = self.usernameB;

crewChief.password = self.passwordB;

crewChief.email = self.emailB;


PFQuery *query = [PFQuery queryWithClassName:@"CrewChiefPhrase"];

[query whereKey:@"Phrase" equalTo:self.phrase.text];

[query countObjectsInBackgroundWithBlock:^(int count, NSError *error) {

    if (count > 0){

        [crewChief signUpInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {

            if (error) {

                UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"Sorry!" message:[error.userInfo 

objectForKey:@"error"] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

                [alertView show];

            }

            else{

                [self.navigationController popToRootViewControllerAnimated:YES];

            }

        }];

    } else {

        UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"Sorry!" message:[error.userInfo 

objectForKey:@"error"] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

        [alertView show];

            }

}];

}

@end '''

please help i dont know how it is possible for the value of these variables to become zero and i dont know what im doing wrong.