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iOS Build a Simple iPhone App with Swift 2.0 Getting Started with iOS Development Swift Recap Part 2

Subclass Machine and create a new class called Robot

Trying to complete the final Challenge Task where I need to use a switch statement to change the location property of the Robot from the subclass method.

classes.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! Im a machine!")
    }
}

// Enter your code below

class Robot: Machine {

override func move(direction: String) {
switch direction {
case "Up": location.y + 1
case "Down": location.y - 1
case "Left": location.x - 1
case "Right": location.x + 1

default: break
}


}

}

3 Answers

Ben Shockley
Ben Shockley
6,094 Points

You've got this pretty much dead on right, you just missed one thing, from what I can tell.

You need to set the coordinate of each movement equal to an increment or decrement. So instead of just saying

case "Up": location.y + 1

You need to say

case "Up": location.y += 1

otherwise it won't actually store that increment once the switch statement exits. When I made this change, it passed the challenge with no issues.

-- Ben

Thank you very much Ben, this works perfectly now!

Pavel Bogart
Pavel Bogart
1,713 Points

an option using switch:

class Robot: Machine {

    override func move(direction: String) {
        switch direction {
            case "Up":
            location.y += 1
            case "Down":
            location.y -= 1
            case "Left":
            location.x -= 1
            case "Right":
            location.x += 1
        default: break
        }
    }

}