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iOS Object-Oriented Swift Classes and Objects Classes and Their Methods

what am i doing wrong, can someone help me??

We need to provide a means to increase the size of our Button. So we are going to add a method named incrementBy which will accept a parameter named points. (Within the method add points to the width and height properties).

class Button {
  var width: Double
  var height: Double

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

  func incrementBy (points: Double) -> Double {
     return width = width * points 
     return height = height * points


1 Answer

William Li
William Li
Courses Plus Student 26,867 Points

Hello, azumi yuan There're several places you need to make change to in your incrementBy method.

  • some methods/functions have no return type, incrementBy is one of those, it just performs increment operation on 2 variables, and it need not return anything. Therefor, -> Double should be deleted.
  • delete the return keyword as well.
  • increment is an addition operation, no multiplication, change * to +.
  func incrementBy (points: Double) {
     width = width + points 
     height = height + points

Now this method should pass the challenge.