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David Perkins
2,028 PointsWhy does it keep saying I need to add the incrementBy() method to class RoundButton? I already am! ...I think
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 = 7.0) {
super.width
super.height
}
}
I'm overriding the function incrementBy and setting the default points parameter to 7.0. I'm not so sure about the super.width and super.height, but it's not saying that they're my problem.
2 Answers
William Li
Courses Plus Student 26,868 PointsTo call the method from the superclass, it needs to be in the format of super.methodname() for it to work here.
class RoundButton: Button {
var cornerRadius: Double = 5.0
override func incrementBy(_ points: Double = 7.0) {
return super.incrementBy(points)
}
}
David Perkins
2,028 PointsThanks William. So I actually tried exactly that before you answered, except for inputting the underscore before the parameter of incrementBy(). Does the underscore apply to all methods without an external parameter name? Or only to overriding ones?
William Li
Courses Plus Student 26,868 PointsIt's for overriding the default behavior. You may check out the Modifying External Parameter Name Behavior for Methods section in Swift doc or this StackOverflow post, they discuss the use of underscore in great length. Hope this helps.