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

Posted by Madina Begumova
Madina Begumova
2,930 Points

Can't understand the issue. Please help

my code is not accepted

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()

    }

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


let player = Robot()
player.location = Point(x: 2, y: 2)
player.move(direction: "Up")

print(player.location.y)

2 Answers

David Papandrew
David Papandrew
8,386 Points
David Papandrew
David Papandrew
8,386 Points

The problem is that the parent Class, Machine, has a function "move" with an external name of "_"

Your subclass function should have the same external name AND you need to remove the parameter name from the player.move statement.

Here's the tweaked code. With comments marking the spots you need to address.

Should pass once you make these changes.

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()

    }

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


let player = Robot()
player.location = Point(x: 2, y: 2)
player.move("Up") // Underscore in the func means no param name, just pass argument

print(player.location.y)
Madina Begumova
Madina Begumova
2,930 Points
Madina Begumova
Madina Begumova
2,930 Points

thank you so much, David! I was able to fix it myself as well :)