How to extract first character and numbers after that until find a character (a-z) in a string - C# 2.0

Question

How to extract numbers from a second index of a string until find a character (az) in a string?

I am using C# version 2.0 (can't upgrade for some reasons).

Here are some examples;

• M000067TGFD45F = M000067
• B000064TFR765TXT = B000064
• B000065TFR765 = B000065
• B000067TGFD = B000067

I have tried Regex("[^0-9]") which works if there is no character after digits (4th example)

 "B" + regexOnlyNumbers.Replace(mystring, string.Empty);

Answer 1

You can use

string text = "M000067TGFD45F";
Match m = Regex.Match(text, @"^[A-Z][0-9]+");
if (m.Success)
{
    Console.WriteLine(m.Value);
}

See the regex demo .

Details

• ^ - start of string
• [AZ] - an uppercase ASCII letter
• [0-9]+ - one or more ASCII digits.

Alternatively, you might consider a ^[AZ][^AZ]+ pattern, where [^AZ]+ matches any one or more chars other than uppercase ASCII letters.

To ignore case, use RegexOptions.IgnoreCase : Regex.Match(text, @"^[AZ][0-9]+", RegexOptions.IgnoreCase) .