Removing duplicate elements from an array in Swift

Question

I might have an array that looks like the following:

[1, 4, 2, 2, 6, 24, 15, 2, 60, 15, 6]

Or, reall

Answer 1

Here is a solution that

• Uses no legacy NS types
• Is reasonably fast with O(n)
• Is concise
• Preserves element order

extension Array where Element: Hashable {

    var uniqueValues: [Element] {
        var allowed = Set(self)
        return compactMap { allowed.remove($0) }
    }
}