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iOS Build a Simple iPhone App with Swift Getting Started with iOS Development Swift Recap Part 2

Posted by Julian Landy
Julian Landy
1,895 Points

Has anyone successfully completed the code challenge, the one where you have to create a new class named robot?

I`m having some what of a difficult time trying to get past this challenge.

robots.swift 
class Point {
  var x: Int
  var y: Int

  init(x: Int, y: Int) {
    self.x = x
    self.y = y
  }
}

class Machine {
  var location: Point

  init() {
    self.location = Point(x: 0, y: 0)
  }

  func move(_ direction: String) {
    print("Do nothing! Im a machine!")
  }
}

// Enter your code below

class Robot: Machine {
  override func move(direction: String){
        switch direction{
            case "Up" : location.y++
            case "Down" : location.y--
            case "Left" : location.x--
            case "Right" : location.x++
            default : break
        }
  }
}

1 Answer

Jason Anders
MOD
Jason Anders
Treehouse Moderator 145,860 Points
Jason Anders
Jason Anders
Treehouse Moderator 145,860 Points

Hey Julian.

What you have is pretty much right on the button, except for 2 things.

  1. The ++ and -- has been deprecated in Swift 3 and is no longer accepted in Xcode. You will need to use the += operator instead.
  2. In your override method, the params pass in need to be the same as the original method you are overriding. You are missing the external variable name (or in this case, the absence of _.

Give it another go. I'm sure you'll have it now. :)

Keep Coding! :dizzy:

Julian Landy
Julian Landy
1,895 Points

Thanks heaps Jason.