Coderbyte - longest word

longest.cs

  private static readonly Regex rx = new Regex(@"\b(\w+)\b");

  public static string LongestWord(string sen) {
    return rx.Matches(sen)
      .Select(m => m.Groups[0].Value)
      .Select(w => Tuple.Create(w, w.Length))
      .OrderByDescending(t => t.Item2)
      .Select(t => t.Item1)
      .FirstOrDefault();
  }