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

I don't understand why these code doesn't pass the code challenge

Can someone helps me to pass 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! I'm a machine!")
  }
}

// Enter your code below

class Robot: Machine {

  override func move(_direction: String) {
      switch _direction {
        case "Up": location.y += 1
        case "Down": location.y -= 1
        case "Right": location.x += 1
        case "Left": location.x -= 1
        default: break
      }
  }
}

1 Answer

David Papandrew
David Papandrew
8,386 Points

Hi Ioana,

Your code has two small typos that are preventing it from passing:

1) You need to escape the single quote in the print statement. Normally this shouldn't be a problem in Xcode, but for some reason it's an issue in the Treehouse editor. It's causing all the subsequent code to appear commented out.

2) The challenge uses the _ (underscore) in the move parameters for the external parameter name. You have removed the space between the external name and "direction". In your code instead of having "_ direction" you have "_direction". This appears in 2 places in your code. You need to fix that too.

Here's the corrected code. It passed when I ran it:

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! I\'m a machine!")
  }
}

// Enter your code below

class Robot: Machine {

  override func move(_ direction: String) {
      switch direction {
        case "Up": location.y += 1
        case "Down": location.y -= 1
        case "Right": location.x += 1
        case "Left": location.x -= 1
        default: break
      }
  }
}

Thank you! ^.^ I didn't see that space there.