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

help on calling the subclass function

its giving me an error that for the up direction y need to increase by 1.but I think my code is right. can somebody assist what I need to correct.

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 {
    var relocation: Point

   override init() {
        self.relocation = Point(x: 0, y: 0)
    }

   override func move(_ direction: String) {

        switch direction {
        case "up": relocation.y += 1
        case "down": relocation.y -= 1
        case "right": relocation.x += 1
        case "left": relocation.x -= 1
        default: break
        }
    }
}

1 Answer

Jeff McDivitt
Jeff McDivitt
23,970 Points

Hi Axon -

  1. There is no need for the variable relocation that you created
  2. There is no need for the override initializer, you are overriding the method
  3. The Cases need to be uppercase and no need for relocation
class Robot: Machine {

   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
        }

    }

}