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


There are no compilation errors but while rechecking the work it's giving the error like "In the up direction increase the y coordinate by 1", but in the code it already increased

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



1 Answer

4,025 Points

you should change the value of location, in your code you are making an operation, but you are nota assigning the result to any variable.

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