So when setting defaults to the let variables of the original class, we need to use the keyword 'override? please expand

Question

I kind of get why but in the examples in the course, only functions were overridden, I just wanna know a bit more as to why we need an override in this case

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
    override init(wheels:Int, doors:Int){
      // call super.init
      super.init(wheels:wheels, doors:doors)
    }
    convenience init () {
        self.init(wheels:4, doors:4)
    }
}

Answer 1 · 2015-03-10T03:43:27Z

March 10, 2015 3:43am

When one class is derived from another, the new class is called the subclass and the class it derives from is called the superclass. The subclass usually adds its own properties and methods to those inherited from the superclass, however a subclass also has the ability to "override" methods and properties of the superclass by actually redefining them itself. In the case of the challenge, the Vehicle class has two 'stored properties' named 'wheels' and 'doors', which ARE given initial values by means of the initializer method. The override keyword is used within a subclass to tell the compiler that the redefinition is intentional, and that you haven't accidentally created a method or property with the same name.

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Abner Medina

Abner Medina

So when setting defaults to the let variables of the original class, we need to use the keyword 'override? please expand

1 Answer

kjvswift93

kjvswift93