let message = "Name: John, Name: George, Name: David"
let regex = /Name:\s+([a-zA-Z]+)/

let matches = message.matches(of: regex)
if !matches.isEmpty {
   let names = matches.map({ value in
      return value.output.1
   })
   let list = names.joined(separator: ", ")
   print("Names are: \(list)")
   // "Names are: John, George, David"
}