Filter non-digits from string

Question

Using only swift code I cant figure out how to take \"(555) 555-5555\" and return only the numeric values and get \"5555555555\". I need to remove all the parentheses, whit

Answer 1

Not exactly answered but it looks like a number. I used URLComponents to build the url because it strips out parenthesis and dashes automatically:

var telUrl: URL? {
    var component = URLComponents()
    component.scheme = "tel"
    component.path = "+49 (123) 1234 - 56789"
    return component.url
}

then

UIApplication.shared.open(telUrl, options: [:], completionHandler: nil)

calls +49 123 123456789