How can I remove or replace all punctuation characters from a String?

Question

I have a string composed of words, some of which contain punctuation, which I would like to remove, but I have been unable to figure out how to do this.

For example if I

Answer 1

String has a enumerateSubstringsInRange() method. With the .ByWords option, it detects word boundaries and punctuation automatically:

Swift 3/4:

let string = "Hello, this : is .. a \"string\"!"
var words : [String] = []
string.enumerateSubstrings(in: string.startIndex.. () in
                                    words.append(substring!)
}
print(words) // [Hello, this, is, a, string]

Swift 2:

let string = "Hello, this : is .. a \"string\"!"
var words : [String] = []
string.enumerateSubstringsInRange(string.characters.indices,
    options: .ByWords) {
        (substring, _, _, _) -> () in
        words.append(substring!)
}
print(words) // [Hello, this, is, a, string]