Regex vs Tryparse what is the best in performance

Question

In my ASP.net project I need to validate some basic data types for user inputs. The data types are like numeric, decimal, datetime etc.

What is the best approach t

Answer 1

As other would say, the best way to answer that is to measure it ;)

    static void Main(string[] args)
    {

        List meansFailedTryParse = new List();
        List meansFailedRegEx = new List();
        List meansSuccessTryParse = new List();
        List meansSuccessRegEx = new List();


        for (int i = 0; i < 1000; i++)
        {


            string input = "123abc";

            int res;
            bool res2;
            var sw = Stopwatch.StartNew();
            res2 = Int32.TryParse(input, out res);
            sw.Stop();
            meansFailedTryParse.Add(sw.Elapsed.TotalMilliseconds);
            //Console.WriteLine("Result of " + res2 + " try parse :" + sw.Elapsed.TotalMilliseconds);

            sw = Stopwatch.StartNew();
            res2 = Regex.IsMatch(input, @"^[0-9]*$");
            sw.Stop();
            meansFailedRegEx.Add(sw.Elapsed.TotalMilliseconds);
            //Console.WriteLine("Result of " + res2 + "  Regex.IsMatch :" + sw.Elapsed.TotalMilliseconds);

            input = "123";
            sw = Stopwatch.StartNew();
            res2 = Int32.TryParse(input, out res);
            sw.Stop();
            meansSuccessTryParse.Add(sw.Elapsed.TotalMilliseconds);
            //Console.WriteLine("Result of " + res2 + " try parse :" + sw.Elapsed.TotalMilliseconds);


            sw = Stopwatch.StartNew();
            res2 = Regex.IsMatch(input, @"^[0-9]*$");
            sw.Stop();
            meansSuccessRegEx.Add(sw.Elapsed.TotalMilliseconds);
            //Console.WriteLine("Result of " + res2 + "  Regex.IsMatch :" + sw.Elapsed.TotalMilliseconds);
        }

        Console.WriteLine("Failed TryParse mean execution time     " + meansFailedTryParse.Average());
        Console.WriteLine("Failed Regex mean execution time        " + meansFailedRegEx.Average());

        Console.WriteLine("successful TryParse mean execution time " + meansSuccessTryParse.Average());
        Console.WriteLine("successful Regex mean execution time    " + meansSuccessRegEx.Average());
    }
}