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

Ryan Maneo
Ryan Maneo
4,342 Points
Posted by Ryan Maneo
Ryan Maneo
4,342 Points

This can't be right... is it?

Do I just keep writing them like that? It doesn't seem right but I don't see any other option

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) {
    /*    switch Point { 
          case Up: return Point(x: 0, y: 1) 
        */
        // Code I added commented out
        }
    }
}

1 Answer

Keli'i Martin
Keli'i Martin
8,227 Points
Keli'i Martin
Keli'i Martin
8,227 Points

You're close. You don't want to actually create a new instance of Point for each case in your switch. move() is an instance method of the Robot class, which just so happens to already have a Point property called location. All you need to do is modify that location's x and y values depending on which case you are checking (ie. .Up, .Down, etc).

Ryan Maneo
Ryan Maneo
4,342 Points
Ryan Maneo
Ryan Maneo
4,342 Points

I'm sorry... I'm still not fully understanding this... what again?

Ryan Maneo
Ryan Maneo
4,342 Points
Ryan Maneo
Ryan Maneo
4,342 Points

I get that but how do I modify it? Do I call it as an instance e.g location(x: 1, y: 1)? or something?

It didn't tell me exactly how much to modify it, up or down, it just said to modify it up or down... confused... UGH

Keli'i Martin
Keli'i Martin
8,227 Points
Keli'i Martin
Keli'i Martin
8,227 Points

I don't remember the exact parameters of the challenge, but I believe you are asked to increment or decrement either the x or the y by 1, depending on which direction you pass into the move() method. So, for example, if you pass in .Up, you would increment the y value by 1. So, your case for that would look like this:

case .Up: location.y += 1

If you pass in .Left, your case would look like

case .Left: location.x -= 1

etc, etc.

Keli'i Martin
Keli'i Martin
8,227 Points
Keli'i Martin
Keli'i Martin
8,227 Points

Also, just as a note, the move() method does not return any values, so you should not try to return in any of your cases.