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iOS Object-Oriented Swift Inheritance What is Inheritance?

Karthikeya Nadendla
Karthikeya Nadendla
9,747 Points
Posted by Karthikeya Nadendla
Karthikeya Nadendla
9,747 Points

What does it mean "You forgot to inherit from Button" ?

I have wrote the code for the Question, So write a subclass named RoundButton which inherits from Button but i'm getting an error. Please let me know how to write the code for that. Thanks

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

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

2 Answers

Martin Wildfeuer
PLUS
Martin Wildfeuer
Courses Plus Student 11,071 Points
Martin Wildfeuer
Martin Wildfeuer
Courses Plus Student 11,071 Points

I am not sure if you have posted your entire code, but take care not to remove the original Button class, because RoundButton will have to be a subclass of Button. This way, you don't have to rewrite variables and functions that RoundButton shares with Button.

So this code should work:

// Button, superclass for RoundButton
class Button {
  var width: Double
  var height: Double

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

// Subclass of Button class
class RoundButton : Button {
    // This class inherits variables and functions
    // from the Button superclass. That is, you
    // can access width and height. You can also
    // use the initializer of Button.
}

The concept of inheritance is a fundamental part of OOP (Object Oriented Programming). Make sure to have a look at the Apple Docs: Inheritance chapter, it's explained in detail there.

Hope that helps! :)