Can somebody please tell me how to do this Regex expression

Question

I have a string and I want to capture the number inside it and then add one to it!.

For example I have an email subject header saying "Re: Hello (1)"

I want to capture that 1 and then raise it by 2, then 3,then 4,etc. The difficulty I am having is taking into consideration the growing numbers, once it becomes say 10 or 100, that extra digit kills my current Regex expression.

      int replyno = int.Parse(Regex.Match(Subject, @"\([0-9]+\)").Value);
      replyno++;
      string Subject = Subject.Remove(Subject.Length - 3);
      TextBoxSubject.Text = Subject + "("+replyno+")";

Post your current regex expression. – Alberto Nov 04 '13 at 14:27 — Alberto, Nov 04 '13 at 14:27
String will always starts from `Re: Hello..`? – vmeln Nov 04 '13 at 14:35 — vmeln, Nov 04 '13 at 14:35

score 2 · Answer 1 · edited May 23 '17 at 12:21

Re: Hello \([0-9]+\)

This matches the string "Re: Hello (1)" with any number of digits as the number, so it also matches "Re: Hello (100)".

Note that I have specifically used [0-9] and not \d to match a digit, because they are different. \d will match numeric characters in other languages, too. See this question and answer for more info: https://stackoverflow.com/a/6479605/1801

If you need to match other numeric characters, you can replace [0-9] with \d

score 1 · Answer 2 · answered Nov 04 '13 at 14:29

1

You may use

\((\d+)\)

as a regular expression. This captures a number inside (), regardless of the numbers size thanks to +.

answered Nov 04 '13 at 14:29

KeyNone

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score 0 · Answer 3 · answered Nov 04 '13 at 14:29

0

Change your regex expression to \d+. That'll help you support multi-digit numbers.

answered Nov 04 '13 at 14:29

David Arno

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Can somebody please tell me how to do this Regex expression

3 Answers3