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iOS Object-Oriented Swift Inheritance Inheritance and Initializers

Adam Bridges
Adam Bridges
1,904 Points
Posted by Adam Bridges
Adam Bridges
1,904 Points

RoundButton designated initializer

What's wrong with my designated initializer for RoundButton? Here's my code:

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

3 Answers

Jens Hagfeldt
Jens Hagfeldt
16,548 Points
Jens Hagfeldt
Jens Hagfeldt
16,548 Points

Hi Adam.

Remember when subclassing another class you always need to also make a call to the base classes initializer to initialize the base classes properties (in this case: width and height). Also remember that this always should be done after initializing the subclasses own properties (in this case: cornerRadius). The call to the base classes initializer is done by adding the line: super.init(width: width, height: height) like below. 

class RoundButton: Button {
  var cornerRadius: Double = 5.0

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

I hope this explanation of mine made sense for you...

Happy coding! / Jens

Jens Hagfeldt
Jens Hagfeldt
16,548 Points
Jens Hagfeldt
Jens Hagfeldt
16,548 Points

I have corrected the typo now... sorry again.

macche
macche
3,989 Points
macche
macche
3,989 Points

Hi Jens, thanks to have fixed it, I just don't understand yet why this is correct:

super.int(width: width, height: width)

and not this:

super.int(width: width, height: height)

I don't get why height: width vs height: height

thanks again

Jens Hagfeldt
Jens Hagfeldt
16,548 Points
Jens Hagfeldt
Jens Hagfeldt
16,548 Points

Sorry for the typo. It should be " height: height "

macche
macche
3,989 Points
macche
macche
3,989 Points

oh ok, thanks. But even with the typo the code passed. Any explanation for it too? thanks for your time :)