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iOS Build a Simple iPhone App with Swift Getting Started with iOS Development Swift Recap Part 2

Maarten De Kruif
Maarten De Kruif
7,314 Points

error: extraneous argument label 'direction:' in call player.move(direction: .up)

Why is the code not working?

robots.swift
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 .up: location.y += 1
            case .down: location.y -= 1
            case .right: location.x += 1
            case .left: location.x -= 1
        }

        print(location.x, location.y)
    }
}

let player = Robot()
player.location = Point(x: 33, y: 2)
player.move(direction: .up)
player.move(direction: .down)

1 Answer

David Papandrew
David Papandrew
8,386 Points

You are receiving the error because the move method doesn't take an external argument label (the underscore indicates this).

So when you make the method call in your final lines of code, you would write it this way:

player.move(.up)
player.move(.down)

Hope that helps.