Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Enumerations and Optionals in Swift Introduction to Enumerations Enums and Objects

Garrick Henne
Garrick Henne
3,868 Points

What does the the move(_ direction: Direction) method output? Why does it still work without one?

I am trying to figure out what the function is supposed to output, i thought it would be -> Point or location but those dont seem to work. But when i complete the function with the output being empty it still works somehow anyway, why is this?

class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int) {
        self.x = x
        self.y = y

enum Direction {
    case left
    case right
    case up
    case down

class Robot {
    var location: Point

    init() {
        self.location = Point(x: 0, y: 0)

    func move(_ direction: Direction) {
        // Enter your code below

1 Answer

Clark Reilly
Clark Reilly
6,204 Points

It shouldn't output anything. It should only change the values of Robot

func move(_ direction: Direction) /* -> nil/void/zip/nada */ {
  switch direction
  case right: location.x += 1
  //You can do the rest from here.