RegExp match in Swift

Question

I use a code from Swift extract regex matches

func matchesForRegexInText(regex: String!, text: String!) -> [String] {

    do {
        let regex = try NSRegularExpression(pattern: regex, options: [])
        let nsString = text as NSString
        let results = regex.matchesInString(text,
            options: [], range: NSMakeRange(0, nsString.length))
        return results.map { nsString.substringWithRange($0.range)}
    } catch let error as NSError {
        print("invalid regex: \(error.localizedDescription)")
        return []
    }
}

I try match this pattern (sample pattern) "^([a-z]+).*?(\d+)$" And if I use it for string "abc.....123" I get as result this full string... But I want to get array of strings ["abc", "123"]

Could you show us the lines of code where you use the function you posted? — mech, Jan 12 '16 at 21:15

score 1 · Accepted Answer · answered Jan 12 '16 at 21:36

You have to get the subranges of the captured groups – the expressions of the regex within the parentheses respectively – with rangeAtIndex() of the first match.
Since the range of the full string is at index 0, start the loop at index 1.

func matchesForRegexInText(regex: String, text: String) -> [String] {
  var result = [String]()
  do {
    let regex = try NSRegularExpression(pattern: regex, options: [])
    let nsString = text as NSString
    if let match = regex.firstMatchInString(text, options: [], range: NSMakeRange(0, nsString.length)) {
      for i in 1..<match.numberOfRanges {
        result.append(nsString.substringWithRange(match.rangeAtIndex(i)))
      }
    }
  } catch let error as NSError {
    print("invalid regex: \(error.localizedDescription)")
  }
  return result
}

PS: Not everything in Swift needs a ? or !. The exclamation marks in the parameter strings are meaningless as none of them is actually considered as optional.

RegExp match in Swift

1 Answers1