How to find which group is matched in NSRegularExpression - regex

Question

I have a regex statement with multiple capture groups which are separated by | operator. How can I find out which capture group is matched? Only way I can think of -for this example- is counting the number of characters if something is matched.
var string = "1234567897"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[a-zA-Z]{2}$)"
var myRegex = NSRegularExpression(pattern: pattern, options: nil, error: nil)!
if let myMatch = myRegex.firstMatchInString(string, options: nil,
range: NSRange(location: 0, length: string.utf16Count)) {
println((string as NSString).substringWithRange(myMatch.rangeAtIndex(0)))
}

Answer 1

I wrote a code which worked for my example. I am sure it can be written better way but it works for now.
Swift 2.3
var string = "123456789"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[wW]{2}$)"
var myRegex = try! NSRegularExpression(pattern: pattern, options: [])
if let myMatch = myRegex.firstMatchInString(string, options: NSMatchingOptions.init(rawValue: 0), range: NSRange(location: 0, length: string.utf16.count)) {
var matchedGroup = 0
for var i in 1..<myMatch.numberOfRanges {
if myMatch.rangeAtIndex(i).length != 0 {
matchedGroup = i
break
}
}
print(matchedGroup)
print((string as NSString).substringWithRange(myMatch.rangeAtIndex(0))) //whatever the range you want to print
}
Swift 3
var string = "123456789"
var pattern = "(^\\d{9}$)|(^\\d{10}$)|(^\\d{13}$)|(^[a-zA-Z]{2}\\d{9}[wW]{2}$)"
var myRegex = try! NSRegularExpression(pattern: pattern, options: [])
if let myMatch = myRegex.firstMatch(in: string, options: NSRegularExpression.MatchingOptions.init(rawValue: 0), range: NSRange(location: 0, length: string.utf16.count)) {
var matchedGroup = 0
for var i in 1..<myMatch.numberOfRanges {
if myMatch.rangeAt(i).length != 0 {
matchedGroup = i
break
}
}
print(matchedGroup)
print((string as NSString).substring(with: myMatch.rangeAt(0))) //whatever the range you want to print
}