Question

I have a regular expression to match 2 different number formats: \=(?[0-9]+)\?|\+(?[0-9]+)\?

This should return 9876543 as its Value for ;1234567890123456?+1234567890123456789012345123=9876543?
and ;1234567890123456?+9876543? What I would like is to be able to return another value along with the matched ‘Value’.

So, for example, if the first string was matched, I’d like it to return:

Value: 9876543 Format:  LongFormat

And if matched in the second string:

Value: 9876543 Format:  ShortFormat

Is this possible?

Answer 1

Another option, which is not quite the solution you wanted, but saves you using two separate regexes, is to use named groups, if your implementation supports it.

Here is some C#:

var regex = new Regex(@'\=(?<Long>[0-9]+)\?|\+(?<Short>[0-9]+)\?'); string test1 = ';1234567890123456?+1234567890123456789012345123=9876543?'; string test2 = ';1234567890123456?+9876543?';  var match = regex.Match(test1); Console.WriteLine('Long: {0}', match.Groups['Long']);     // 9876543 Console.WriteLine('Short: {0}', match.Groups['Short']);   // blank match = regex.Match(test2); Console.WriteLine('Long: {0}', match.Groups['Long']);     // blank Console.WriteLine('Short: {0}', match.Groups['Short']);   // 9876543 

Basically just modify your regex to include the names, and then regex.Groups[GroupName] will either have a value or wont. You could even just use the Success property of the group to know which matched (match.Groups[‘Long’].Success).

UPDATE: You can get the group name out of the match, with the following code:

static void Main(string[] args) {     var regex = new Regex(@'\=(?<Long>[0-9]+)\?|\+(?<Short>[0-9]+)\?');     string test1 = ';1234567890123456?+1234567890123456789012345123=9876543?';     string test2 = ';1234567890123456?+9876543?';      ShowGroupMatches(regex, test1);     ShowGroupMatches(regex, test2);     Console.ReadLine(); }  private static void ShowGroupMatches(Regex regex, string testCase) {     int i = 0;     foreach (Group grp in regex.Match(testCase).Groups)     {         if (grp.Success && i != 0)         {             Console.WriteLine(regex.GroupNameFromNumber(i) + ' : ' + grp.Value);         }         i++;     } } 

I’m ignoring the 0th group, because that is always the entire match in .NET