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

Bartosz Kulasiewicz
Bartosz Kulasiewicz
1,130 Points

HELP ME PLEASE

In the editor you've been provided with two classes: Point to represent a coordinate point, and Machine. The machine has a move method that doesn't do anything.

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:

If you enter the string "Up" the y coordinate of the Robot's location increases by 1. "Down" decreases it by 1. If you enter "Left", the x coordinate of the location property decreases by 1 while "Right" increases it by 1.

Note: If you use a switch statement you can use the break statement in the default clause to exit the current iteration.

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 am a machine!")
  }
}
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
    }
  }
}

1 Answer

Joseph Heydorn
Joseph Heydorn
iOS Development with Swift Techdegree Graduate 11,421 Points

Hello Bartosz! You're so close to finishing the task! In your override func method, you were simply missing the "_" before direction! Below is the correct code! One thing I suggest is to try out the code inside of a swift playground. I found that this helps to understand the errors a lot better. Good luck and happy coding!

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
    }
  }
}