piyushdec

//to register to catch a notification being posted, use this:
let nc = NotificationCenter.default
nc.addObserver(self, selector: #selector(userLoggedIn), name: Notification.Name("UserLoggedIn"), object: nil)

piyushdec

let aMovement = Movement.left

switch aMovement {
  case .left: print("left")
  default: ()
}

if case .left = aMovement { 
  print("left")
}

piyushdec

// Mapping to Integer
enum Movement: Int {
    case left = 0
    case right = 1
    case top = 2
    case bottom = 3
}

// You can also map to strings
enum State: String {

piyushdec

// mercury = 1, venus = 2, ... neptune = 8
enum Planet: Int {
    case mercury = 1, venus, earth, mars, jupiter, saturn, uranus, neptune
}

// North = "North", ... West = "West"
enum CompassPoint: String {
    case north, south, east, west
}

piyushdec

enum Device {
  enum Phone {
    case iPhone
    case pixel
    case galaxy
    case prius
  }
  enum Laptop {
    case macbook
    case chromebook

piyushdec

let device = Device.googleHome
let phone = Device.Phone.iPhone
let laptop = Device.Laptop.chromeBook

piyushdec

struct Device {
  enum Phone {
    case iPhone
    case pixel
    case galaxy
    case prius
  }
  enum Laptop {
    case macbook
    case chromebook

piyushdec

enum Trade {
    case buy(stock: String, amount: Int)
    case sell(stock: String, amount: Int)
}
func trade(type: Trade) {}

piyushdec

//If you want to access this information, again, pattern matching comes to the rescue:

let trade = Trade.buy(stock: "APPL", amount: 500)
if case .buy(stock, amount) = trade {
    print("buy \(amount) of \(stock)")
}

piyushdec

let tp = (stock: "TESLA", amount: 100)
let trade = Trade.sell(tp)

if case .sell(stock, amount) = trade {
    print("buy \(amount) stocks of \(stock)")
}
//prints: "buy 100 stocks of TESLA