using System;

using System.Text.RegularExpressions;

using System.Reflection;

public class Program

{

    public static void Main()

    {

        int max = 10000;

        TimerExpression("TryParse", 

        () =>

        {

            for (int i = 0; i < max; i++)

            {

                int value = 0; 

                Int32.TryParse(i.ToString(), out value);

            }

        });

        TimerExpression("Regex", 

        () =>

        {

            for (int i = 0; i < max; i++)

            {

​

                Regex.IsMatch(i.ToString(), @"\d");

            }

        });

​

        TimerExpression("PHP IsNumeric",

        () =>

        {

            for (int i = 0; i < max; i++)

            {

                i.ToString().IsNumeric();

            }

        });

​

        TimerExpression("Reflections TryParse",

        () =>

        {

            for (int i = 0; i < max; i++)

            {

​

                i.ToString().ParseAs<int>(0);

            }

        });

    }

​

    public static void TimerExpression(string label, Action call)

    {

        var watch = System.Diagnostics.Stopwatch.StartNew();

        call.DynamicInvoke();

        watch.Stop();

        System.Console.WriteLine(label + " " + watch.ElapsedMilliseconds.ToString());

    }

}

​

public static class StringExtension

{

    public static TOutput ParseAs<TOutput>(this string value, TOutput defaultValue)

    {

        var type = typeof(TOutput);

            var tryParseMethod = type.GetMethod("TryParse", BindingFlags.Static | BindingFlags.Public, Type.DefaultBinder, new[] { typeof(string), type.MakeByRefType() }, null);

        if (tryParseMethod == null) return defaultValue;

        var arguments = new object[] { value, null };

        return ((bool)tryParseMethod.Invoke(null, arguments)) ? (TOutput)arguments[1] : defaultValue;

    }

​

    static readonly Regex _isNumericRegex =

    new Regex("^(" +

                /*Hex*/ @"0x[0-9a-f]+" + "|" +

                /*Bin*/ @"0b[01]+" + "|" +

                /*Oct*/ @"0[0-7]*" + "|" +

                /*Dec*/ @"((?!0)|[-+]|(?=0+\.))(\d*\.)?\d+(e\d+)?" +

                ")$");

    public static bool IsNumeric(this string value)

    {

        return _isNumericRegex.IsMatch(value);

    }

​

}

​