let possibleNumbers = ["1", "2", "three", "///4///", "5"]

let mapped: [Int?] = possibleNumbers.map { str in Int(str) }
print(mapped)
// [1, 2, nil, nil, 5]

let compactMapped: [Int] = possibleNumbers.compactMap { str in Int(str) }
print(compactMapped)
// [1, 2, 5]