Enums

Enums define a group of related values in a type-safe way. They are particularly useful for defining states, options, or categories that a variable can have.

enum CompassPoint {
    case north
    case south
    case east
    case west
}

var direction = CompassPoint.north

switch direction {
case .north:
    print("Heading North")
case .south:
    print("Heading South")
case .east:
    print("Heading East")
case .west:
    print("Heading West")
}

//Output
print("Heading North")

Raw Values

Enums can have raw values associated with each case. The raw value must be of the same type and unique.

enum Planet: Int {
    case mercury
    case venus
    case earth
    case mars
}
print(Planet.mercury.rawValue) 

// Output
 0

enum Seasons: String {
    case spring = "Blossoms"
    case summer = "Heat"
    case winter = "Snow"
}

print(Seasons.winter.rawValue) 
// Outputs: Snow

Associated Values

Enums can store additional associated values for each case.

enum Barcode {
    case upc(Int, Int, Int, Int)
    case qrCode(String)
}

var productCode = Barcode.upc(8, 85909, 51226, 3)

switch productCode {
case .upc(let numberSystem, let manufacturer, let product, let checkDigit):
    print("UPC: \(numberSystem)-\(manufacturer)-\(product)-\(checkDigit)")
case .qrCode(let code):
    print("QR Code: \(code)")
}

//Output
UPC: 8-85909-51226-3

Enum with Function

enum TrafficLight {
    case red, yellow, green

    func action() -> String {
        switch self {
        case .red:
            return "Stop"
        case .yellow:
            return "Get Ready"
        case .green:
            return "Go"
        }
    }
}

let light = TrafficLight.red
print(light.action()) 

// Output
 Stop

Enum with CaseIterable

enum Beverage: CaseIterable {
    case coffee, tea, juice
}

for beverage in Beverage.allCases {
    print(beverage)
}

//Output
coffee
tea
juice