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

Posted by Allen Deckert
Allen Deckert
9,783 Points

No Errors but Not Passing Challenge Build Simple iPhone App Swift 3

Not throwing any errors but I can't seem to find out what was wrong. Looked for previous answers to this question and assumed that the challenge is still bugged because of the single quotation mark. but putting \ didn't fix it.

robots.swift 
class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int){
        self.x = x
        self.y = y
    }
}


class Machine {
    var location: Point

    init() {
        self.location = Point(x: 0, y: 0)
    }

    func move(direction: String) {
        print("Do nothing! I\'m a machine!")
    }
}

// Enter your code below
class Robot: Machine {
    override func move(direction: String) {
        switch direction {
        case "Up": self.location.y += 1
        case "Down": self.location.y -= 1
        case "Left": self.location.x += 1
        case "Right": self.location.x -= 1
        default: break
        }
    }
}

2 Answers

Thomas Dobson
Thomas Dobson
7,511 Points

Hi Allen,

Xcode did not produce the error, but the Treehouse compiler did:

swift_lint.swift:32:19: error: argument names for method 'move(direction:)' do not match those of overridden method 'move' override func move(direction: String) {

looking closer at your code I see two mistakes (See comments):

class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int){
        self.x = x
        self.y = y
    }
}


class Machine {
    var location: Point

    init() {
        self.location = Point(x: 0, y: 0)
    }

    func move(direction: String) { //You removed the internal name omitance "_" before direction
        print("Do nothing! I\'m a machine!")
    }
}

// Enter your code below
class Robot: Machine {
    override func move(direction: String) { //You removed the internal name omitance "_" before direction
        switch direction {
        case "Up": self.location.y += 1
        case "Down": self.location.y -= 1
        case "Left": self.location.x += 1        // Left is -=
        case "Right": self.location.x -= 1      // Right is +=
        default: break
        }
    }
}

The final code being:

class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int){
        self.x = x
        self.y = y
    }
}


class Machine {
    var location: Point

    init() {
        self.location = Point(x: 0, y: 0)
    }

    func move(_ direction: String) {
        print("Do nothing! I\'m a machine!")
    }
}

// Enter your code below
class Robot: Machine {
    override func move(_ direction: String) { 
        switch direction {
        case "Up": self.location.y += 1
        case "Down": self.location.y -= 1
        case "Left": self.location.x -= 1
        case "Right": self.location.x += 1
        default: break
        }
    }
}

Your code compiled fine in Xcode... just not quite what the parameters of the exercise was expecting.

Allen Deckert
Allen Deckert
9,783 Points
Allen Deckert
Allen Deckert
9,783 Points

Thank you!