public class Example
{
   public static void Main()
   {
      Regex rgx = new Regex(@"\d*\.\d?");
 
      // Define some test strings.
      string[] tests = { "-42", "19.99", "0.001", "100 USD", 
                         ".34", "0.34", "1,052.21", "$10.62", 
                         "+1.43", "-$0.23" };
 
      // Check each test string against the regular expression.
      foreach (string test in tests)
      {
         if (rgx.IsMatch(test))
            Console.WriteLine("{0} is a currency value.", test);
         else
            Console.WriteLine("{0} is not a currency value.", test);
      }
   }
}

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