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iOS Swift 2.0 Enumerations and Optionals Introduction to Enumerations Enums and Objects

Andrei K
Andrei K
7,601 Points
Posted by Andrei K
Andrei K
7,601 Points

Attempting to complete the enum challenge task

Hi, I'm trying to complete the enum challenge task. I'm a bit lost, I don't see how I can add to or subtract from the initialized values in the Point() function. Any help?

classes.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) {
        case Direction.Up {
            self.location = Point(y = y+1)
        }
        case Direction.Down {
            self.location = Point(y = y-1)
        }
        case Direction.Left {
            self.location = Point(x = x-1)
        }
        case Direction.Right {
            self.location = Point(x = x+1)
        }
    }
}

1 Answer

Nathan Tallack
Nathan Tallack
22,160 Points
Nathan Tallack
Nathan Tallack
22,160 Points

Your logic was good. Just a few syntax errors. I've corrected them below and given comments on each of them.

In addition I've given you some shortcuts on your syntax and commented them too. :)

    func move(direction: Direction) {
        // We need to switch on the parameter we pass in.
        switch direction {  // The code block contains all the cases inside the braces.
            case .Up:  // Each case separates what it is from what it does with a :
                self.location.y += 1  // We reference the location object property for y like this.
            case .Down:  // We can leave out the Direction and start with . for the known type.
                self.location.y -= 1
            case .Left:
                self.location.x -= 1
            case .Right:
                self.location.x += 1
        }
    }

Keep up the good work!!!