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

Posted by trentabaldwin
trentabaldwin
20,473 Points

Why does the y value not increase?

Why can I not change the value of the Robot's coordinates?

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

1 Answer

Steve Hunter
Steve Hunter
57,712 Points

Hi there,

You have your move method inside your init method. You need to put it outside of init and then make sure you override it too.

Something like:

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

I removed the call to super init too as that doesn't need to be there. I hope that makes sense.

Steve.

trentabaldwin
trentabaldwin
20,473 Points

Thank you!

Steve Hunter
Steve Hunter
57,712 Points

:+1: