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

Posted by heather wolfram
heather wolfram
1,594 Points

What is wrong with my code?

I have already requested help with this code multiple times and nothing has worked so far. I am just about crazy from thinking! What am I doing wrong? Is there possibly something wrong with Treehouse that is not allowing for my code to go through??

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

 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

andren
andren
28,558 Points
andren
andren
28,558 Points

It's not an issue with the challenge, the instructions for this task specify:

Your task is to subclass Machine and create a new class named Robot. In the Robot class, override the move method and provide the following implementation.

You have done the second part of that but not the first, an overridden method can't exist in a vacuum. It needs to be inside a class which inherits from a class that has the same method already defined. If that is not the case there wouldn't be a point to overriding it in the first place.

If you make a Robot class that inherits from the Machine class and paste your code into it like this:

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 { // Create a class that inherit from the Machine class.
    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
        }
    }
}

Then your code will pass.