Struct userModel {
   var firstName: String
   var lastName: String
   var userID: int
   var weight: float?
   var age: int?
   var email: String
   var country: String?
   var height: float?
   var goalWeight: float?

   Init( fname: String, lname: String, ID: Int, userWeight: float?, userAge: int?, userEmail: String, userCountry: String?, userHeight: float?,  userGoalWeight: float?){
      self.firstName = fname
      self.lastName = lname
      self.userID = ID
      self.weight = userWeight
      self.age = userAge
      self.email = userEmail
      self.country = userCountry
      self.height = userHeight
      self.goalWeight = userGoalWeight
   }


}

Extention userModel{
   func validateUserForLogin(username: String,  password: String) -> Bool{
      //check the username and password against a database
      If username && password {
         //if the password is good to go return true
         Return true
      }else{
         //Display popup error
         Return false
      }
   }
   Mutating func update(userWeight: float){
      Self.weight = userWeight
   }
   Mutating func update(userHeight: float){
      Self.height = userHeight
   }
}