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

Need help with enum

It keeps telling me

Cannot convert value of type '(Direction) -> ()' to expected argument type '_?'

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 move {
      case Direction.up: y += 1

1 Answer

Jhoan Arango
Jhoan Arango
14,575 Points


You are trying to switch on the "Function name" instead you have to switch on the "parameter name" which in this case is "direction". Also you have to finish the implementation of all the possible outcomes in the direction enum, to make it "exhaustive".

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

Good luck