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

Gabriel Spranger Rojas
Gabriel Spranger Rojas
7,350 Points

What's missing?

Please help I'm clueless.

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
        switch direction {
        case .up : Robot().location.y + 1
        case .down : Robot().location.y - 1
        case .right : Robot().location.x + 1
        case .left : Robot().location.x - 1

1 Answer

Simon Di Giovanni
Simon Di Giovanni
8,429 Points

Hi Gabriel

You were REALLY close with this one! Great job.

With this, it's important to remember scope.

Here is the correct code to use

func move(_ direction: Direction) {
        switch direction {
        case .up : location.y += 1
        case .down : location.y -= 1
        case .right : location.x += 1
        case .left : location.x -= 1

As you can see, I have removed 'Robot()'This is not needed, because you are INSIDE Robot()! So you have access to 'location' in the function, because 'location' only exists within Robot()!

Also, when incrementing a value by 1, use '+=' or "-=" (not just + or -) to increment by the given value

If this doesn't make sense please let me know.