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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
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
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
    }
  }
}