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iOS Object-Oriented Swift Class Inheritance Creating a Subclass

Margarita Garmutė
Margarita Garmutė
2,136 Points
Posted by Margarita Garmutė
Margarita Garmutė
2,136 Points

Can anyone help me with subclassing and inherence.

Can't understand what's wrong.

Thanks for help.

objects.swift 
class Vehicle {
  var numberOfDoors: Int
  var numberOfWheels: Int

  init(withDoors doors: Int, andWheels wheels: Int) {
      self.numberOfDoors = doors
      self.numberOfWheels = wheels
  }
}

// Enter your code below


class Car : Vehicle {
    var numberOfSeats: Int = 4

     convenience init(withDoors doors: Int, andWheels wheels: Int, withSeats seats: Int) {

        self.init(withDoors: 5, andWheels: 4, withSeats: 4)
        self.numberOfSeats = seats
       }

}

let someCar = Car(withDoors: 5, andWheels: 4, withSeats: 4)

2 Answers

Jeff McDivitt
Jeff McDivitt
23,970 Points
Jeff McDivitt
Jeff McDivitt
23,970 Points

You are not a need for the initialization in the Car class, the below is what the task is asking for:

class Vehicle {
    var numberOfDoors: Int
    var numberOfWheels: Int

    init(withDoors doors: Int, andWheels wheels: Int) {
        self.numberOfDoors = doors
        self.numberOfWheels = wheels
    }
}

class Car: Vehicle {

    var numberOfSeats: Int = 4
}

let someCar = Car(withDoors: 4, andWheels: 4)

However if you did need to override the initialization you would do it like below

class Vehicle {
    var numberOfDoors: Int
    var numberOfWheels: Int

    init(withDoors doors: Int, andWheels wheels: Int) {
        self.numberOfDoors = doors
        self.numberOfWheels = wheels
    }
}

class Car: Vehicle {

    var numberOfSeats: Int

    override init(withDoors doors: Int, andWheels wheels: Int) {
        self.numberOfSeats = 4
        super.init(withDoors: 4, andWheels: 4 )

    }
}

let someCar = Car(withDoors: 4, andWheels: 4)