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iOS Object-Oriented Swift Inheritance What is Inheritance?

Posted by Ian Underwood
Ian Underwood
2,430 Points

I want to create an instance of the RoundButton class, what's wrong with my code?

I want to create an instance of the RoundButton class and store it in a variable but haven't been able to

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

  init(width:Double, height:Double){
    self.width = width
    self.height = height
  }
  class RoundButton: Button{
  var cornerRadius = 5.0
  }
  var rounded = RoundButton(width: 10.0, height: 10.0)
}

2 Answers

Robert Richey
PLUS
Robert Richey
Courses Plus Student 16,352 Points
Robert Richey
Robert Richey
Courses Plus Student 16,352 Points

Hi Ian,

Your code is fine, except that classes cannot be defined inside other classes. It's a mistake that the challenge accepted your code when creating the subclass. Here is what the code should look like:

class Button {
  var width: Double
  var height: Double

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

class RoundButton: Button{
  var cornerRadius = 5.0
}

var rounded = RoundButton(width: 10.0, height: 10.0)

Hope this helps,

Cheers

Ritesh Malik
Ritesh Malik
Courses Plus Student 1,700 Points

But Sir when i try the same in xcode it shows no error as below:

class Button {

    var width: Double

    var height: Double

    init(width:Double, height:Double){

        self.width = width

        self.height = height

    }
}


class RoundButton: Button {

  var cornerRadius: Double = 5.0

    var round = RoundButton(width: 5.0, height: 10.0)
}
Robert Richey
Robert Richey
Courses Plus Student 16,352 Points

Hi Ritesh,

I added markdown to your code to make it more readable.

Your code is almost identical to mine, which is the fix to Ian's code - separating class definitions.

Ritesh Malik
Ritesh Malik
Courses Plus Student 1,700 Points

okay sir i thought we are supposed to make rounded instance specifically outside both the classes. Thanks sir

Ian Underwood
Ian Underwood
2,430 Points
Ian Underwood
Ian Underwood
2,430 Points

Ok, thanks for the help! Robert Richey