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iOS Object-Oriented Swift Value vs Reference Types Final Challenge

Alain Readman Valiquette
Alain Readman Valiquette
14,546 Points

Hi, I can't figure out what I do wrong, the code even matches the answer in the forum.

What am I doing wrong?

Vehicle.swift
class Vehicle {
    let wheels: Int
    let doors: Int

    // Designated initializer
    init(wheels:Int, doors:Int){
    self.wheels = wheels
    self.doors = doors   
    }
}

class Car: Vehicle {
    // A car must default to 4 wheels and 4 doors
    init(_wheels: Int = 4, _doors: Int = 4){
      // call super.init
      super.init(wheels: wheels, doors: doors)
    }
}

1 Answer

Greg Kaleka
Greg Kaleka
39,019 Points

Edit: The code below works, but it's actually probably not what you want to do. Instead, you want to override the normal initializer, using the keyword override, and not use your underscores at all:

class Vehicle {
    let wheels: Int
    let doors: Int

    // Designated initializer
    init(wheels:Int, doors:Int){
    self.wheels = wheels
    self.doors = doors   
    }
}

class Car: Vehicle {
    // A car must default to 4 wheels and 4 doors
    override init(wheels: Int = 4, doors: Int = 4){
      // call super.init
      super.init(wheels: wheels, doors: doors)
    }
}

Hi! You're very close - you just need to pass super.init() the parameters from the function definition, which include underscores. Here's the correct code:

class Vehicle {
    let wheels: Int
    let doors: Int

    // Designated initializer
    init(wheels:Int, doors:Int){
    self.wheels = wheels
    self.doors = doors   
    }
}

class Car: Vehicle {
    // A car must default to 4 wheels and 4 doors
    init(_wheels: Int = 4, _doors: Int = 4){
      // call super.init
      super.init(wheels: _wheels, doors: _doors)
    }
}