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iOS Object-Oriented Swift Inheritance Overriding Methods

Posted by William Mordan
William Mordan
2,756 Points

RoundButton code works correctly. Why does the lesson check fail?

See attached playground including test code.

Button.swift 
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) {
         width += points
        height += points
    }
}
William Mordan
William Mordan
2,756 Points

I am puzzled because these outputs look correct:

//These tests look good////////////////////////////////// button.incrementBy() -- width 17, height 27, .cornerRadius 5 button.incrementBy(3) -- width 13, height 23, .cornerRadius 5

1 Answer

Steve Hunter
Steve Hunter
57,712 Points

Hi William,

I think the challenge compiler test is looking for an underscore prior to your points parameter:

override func incrementBy(_ points: Double = 7.0) {

There have been changes with Swift's handling of default parameters so I don't think the underscore is required any more except when escaping a keyword being used as a parameter name. It is worth checking the documentation to check.

Steve.