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

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.

Thank you!