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

Don't understand why I can't pass it

Don't understand why I can't pass it

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) -> Point {
        // Enter your code below

       switch direction {

        case .up: return location.y += 1
        case .down: return location.y -= 1
        case .left: return location.x -= 1
        case .right: return location.x += 1


3 Answers

Michael Hulet
Michael Hulet
Treehouse Moderator 47,826 Points

Your code currently has some errors with the type system. You've specified that the move(_:) function should return a Point object, but it currently returns Void in all cases. In Swift, none of the assignment operators return a value like they do in Objective-C. Instead, they just return Void in all cases.

That being said, in the starter code for the challenge move(_:) is actually supposed to return Void. That's why it doesn't specify a return type. In Swift, when you omit a function's return type, it is assumed to return Void. If you remove your function's return type and all of the return statements within the function, I believe it should pass the challenge. Great job!

thks but just one detail it's asking me to return a value!

Michael Hulet
Michael Hulet
Treehouse Moderator 47,826 Points

Is this in an error message? The challenge's instructions don't say that it needs to return a value. In fact, adding a return value to the move(_:) function will make it an entirely different function in the eyes of Swift than the one that the challenge is expecting to test

ok got it, got confused with the return of the function and the enum . thks