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

vivek d
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vivek d
iOS Development Techdegree Student 1,596 Points

whats wrong with this?

whats missing?

test.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) {
        // Enter your code below
        switch Direction {
        case Direction.up:
            return location.y += 1
        case Direction.down :
            return location.y -= 1
        case Direction.right:
            return location.x += 1
        case Direction.left:
            return location.x -= 1
        }
    }
}

1 Answer

Simple mistake:

When you create a switch case, you have to switch off of some variable that is of type Enum. This variable will contain ONE of the possible cases in the switch case. Then you go throughout the process of the switch case, and you perform some action for each case.

Looks like you put in an enum type Direction into the switch case. Well, this is an enum type, it doesn't contain a case. You have to pass in direction to the switch statement instead. This contains a case, as it's the parameter passed in the function.