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

Zac Duvall
Zac Duvall
3,662 Points
Posted by Zac Duvall
Zac Duvall
3,662 Points

Need some help with this 'switch' Note.

2 questions.

  1. how exactly would I use a String that says "Up" or "Down" to modify the 'location'

  2. the Note of using a switch statement 'break', this bit doesn't make too much sense to me

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!")
  }
}


class Robot: Machine {

    override func move(_ direction: String) {


        print("Do nothing! I'm a machine!")
    }
}

1 Answer

Jeff McDivitt
Jeff McDivitt
23,970 Points
Jeff McDivitt
Jeff McDivitt
23,970 Points
  1. how exactly would I use a String that says "Up" or "Down" to modify the 'location'

You would use a switch statement with the String as a case

  1. the Note of using a switch statement 'break', this bit doesn't make too much sense to me

You need to use break to make the switch statement exhaustive

class Robot: Machine {

    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
        }
    }
}