var airports = ["YYZ": "Toronto Pearson", "DUB": "Dublin"]
 
print("The airports dictionary contains \(airports.count) items.")
// Mencetak "The airports dictionary contains 2 items."
 
if airports.isEmpty {
  print("The airports dictionary is empty.")
} else {
  print("The airports dictionary is not empty.")
}
// Mencetak "The airports dictionary is not empty."
 
airports["LHR"] = "London"
// sekarang dictionary airports berisi 3 items
 
airports["LHR"] = "London Heathrow"
// nilai dari "LHR" akan berubah menjadi "London Heathrow"
 
if let oldValue = airports.updateValue("Dublin Airport", forKey: "DUB") {
  print("The old value for DUB was \(oldValue).")
}
// Mencetak "The old value for DUB was Dublin."
 
if let removedValue = airports.removeValue(forKey: "DUB") {
  print("The removed airport's name is \(removedValue).")
} else {
  print("The airports dictionary does not contain a value for DUB.")
}
// Mencetak "The removed airport's name is Dublin Airport."
 
for (airportCode, airportName) in airports {
  print("\(airportCode): \(airportName)")
}
// LHR: London Heathrow
// YYZ: Toronto Pearson
 
for airportCode in airports.keys {
  print("Airport code: \(airportCode)")
}
// Airport code: LHR
// Airport code: YYZ
 
for airportName in airports.values {
  print("Airport name: \(airportName)")
}
// Airport name: London Heathrow
// Airport name: Toronto Pearson
 
let airportCodes = [String](airports.keys)
// airportCodes adalah ["LHR", "YYZ"]
let airportNames = [String](airports.values)
// airportNames adalah ["London Heathrow", "Toronto Pearson"]