using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?:\bdigit-|\s|^)(\d{4})(?=[.?\s]|-digit\b|$)";
string input = @"Lorem ipsum 3400-digit, sit amet 5000 consectetur adipisicing elit. Natus, explicabo 6700? Itaque iure ipsum laboriosam, ex nemo delectus iste quia cupiditate digit-9134? Iste nam digit-2456 at voluptate est 8456-digit? At excepturi quis voluptatibus 7500.
Lorem ipsum $5000 dolor sit amet consectetur adipisicing elit. Obcaecati tempora dolorum repellat reiciendis cum soluta deserunt ex voluptatibus, nam illum veniam £5550 quidem aperiam sequi, nostrum sed? Quidem eveniet maiores #5550 autem. https://codepen.io/pen/5000/3454
follows either digit- or whitespace and is followed by either ., ?, -digit or whitespace.";
RegexOptions options = 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