How can I put each word of a string into an array in Swift?

Is it possible to put each word of a string into an array in Swift?

for instance:

var str = "Hello, Playground!"

to:

var arr = ["Hello","Playground"]

Thank you :)

edit/update:

Xcode 10.2 • Swift 5 or later

We can extend StringProtocol using collection split method

func split(maxSplits: Int = Int.max, omittingEmptySubsequences: Bool = true, whereSeparator isSeparator: (Character) throws -> Bool) rethrows -> [Self.SubSequence]

setting omittingEmptySubsequences to true and passing a closure as predicate. We can also take advantage of the new Character property isLetter to split the string.

extension StringProtocol {
    var words: [SubSequence] {
        return split { !$0.isLetter }
    }
}

let sentence = "• Hello, Playground!"
let words = sentence.words // ["Hello", "Playground"]