Transform an array
Transform every element, or discard nil results.
let names = ["swift", "foundation"]
print(names.map { $0.uppercased() })
let input = ["12", "oops", "7"]
print(input.compactMap { Int($0) })How it works
map keeps the element count. compactMap transforms each element and drops nil results. This is useful for optional parsing, but can hide invalid input.
EXPECTED OUTPUT
["SWIFT", "FOUNDATION"] [12, 7]
Keep in mind
Track invalid inputs separately when validation failures matter.