Twelve Days

var alreadyGave = [String]()
let formatter = NumberFormatter()
formatter.numberStyle = .ordinal

[
    "A partridge in a pear tree.",
    "Two turtle doves",
    "Three french hens",
    "Four calling birds",
    "Five gold rings",
    "Six geese a-laying",
    "Seven swans a-swimming",
    "Eight maids a-milking",
    "Nine ladies dancing",
    "Ten lords a-leaping",
    "Eleven pipers piping",
    "Twelve drummers drumming"
].forEach {
    alreadyGave.append($0.lowercased())
    let dayOf = formatter.string(for: alreadyGave.count)!
    print("On the \(dayOf) day of Christmas, my true love sent to me: ")
    if alreadyGave.count > 1 {
        print(alreadyGave
                .reversed()
                .dropLast()
                .joined(separator: ", ") + " and " + alreadyGave.first!)
    } else {
        print($0)
    }
}