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iOS Object-Oriented Swift Inheritance Overriding Methods

Joseph Kandi
Joseph Kandi
2,640 Points
Posted by Joseph Kandi
Joseph Kandi
2,640 Points

How do you override a method and provide a default to the overridden method?

I have overridden the incerementBy function but is give me an error when i add a default points: Double = 7.0, if i do remove it then i also get an error that i did not add a default value to the points parameter. Am not sure how to accomplish this task.

Button.swift 
class Button {
  var width: Double
  var height: Double

  init(width:Double, height:Double){
    self.width = width
    self.height = height
  }

  func incrementBy(points: Double){
    width += points
    height += points
  }
}

class RoundButton: Button {
  var cornerRadius: Double = 5.0

   override func incrementBy(points: Double){
    self.width += points
    self.height += points
   }
}

1 Answer

Sjors Theuns
Sjors Theuns
6,091 Points
Sjors Theuns
Sjors Theuns
6,091 Points

Hi Joseph,

you forgot to specify that the parameter points has now a default value. So you need to add an underscore like so:

   override func incrementBy(_ points: Double = 7.0){
    self.width += points
    self.height += points
   }

That should do the trick.

Joseph Kandi
Joseph Kandi
2,640 Points
Joseph Kandi
Joseph Kandi
2,640 Points

Thanks, just realized the moment you answered