using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^ # Start of string
\#? # Optional ""#""
[a-z]{4} # Followed by 4 letters
\ ? # Optional space
_ # Followed by an underscore
[ ]? # Optional space
[0-9]{6} # Followed by 6 digits
[#]? # Optional ""#""
$ # End of string";
string input = @"abcd_123456
abcd _ 123456
#abcd_123456
abcd_123456#
#abcd_123456#
#abcd _ 123456#";
RegexOptions options = RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx