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

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

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.

Thank you!

:+1: