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Eli MBS
1,158 PointsChallenge: Build a Simple iPhone App with Swift 2.0
Hey Guys! Would be glad if someone could explain me how this switch here works... I don't get it.
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 ??? {
case "Up": y += 1
case "Down": y -= 1
case "Left": x += 1
case "Right": x -= 1
default:
break
}
}
}
2 Answers
David Papandrew
8,386 PointsHi Eli,
The switch statement is checking all the cases of the "direction" parameter in the move function. When move is called, a direction needs to be provided (using the object type of "String"). The switch statement then lets you handle all the possible values that the function might provide as input.
Here is how the correct switch statement would look:
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
}
}
}
William Crawford
4,319 PointsThanks, David. I also got stuck here - did not use self.location.y or .x - etc. Thanks!