Designated Initializer Pattern

Ha tobb init method is van egy Class-on akkor azt hivjuk Designated Intializer-nek amelyik valoban beallitja az instancia valtozokat (es meghivja a superclass init-jet). A tobbi init pedig ezt hivja.
pl.:
- (id)initWithFirstName:(NSString *)aFirstName lastName:(NSString *)aLastName dateOfBirth:(NSDate *)aDOB {
    //set properties
}

- (id)initWithFirstName:(NSString *)aFirstName lastName:(NSString *)aLastName {
    return [self initWithFirstName:aFirstName lastName:aLastName dateOfBirth:nil];
}

- (id)init {
    return [self initWithFirstName:@"John" lastName:@"Doe" dateOfBirth:nil];
}