A sample on using flatMap for filtering out nils from an array of String optionals.

SailorGreetingFlatMap.swift

let sailorNames: [String?] = [
	nil,
	"Daffy Duck",
	"Donald Duck",
	nil,
	"Darkwing Duck",
	"Howard The Duck",
]

let unwrappedSailorNames = sailorNames.flatMap({ $0 })

for sailorName in unwrappedSailorNames {
	print(createGreetings(sailorName: sailorName))
}