Reverse a string

 
using System;
using System.Text;

class MainClass
{
    public static string ReverseString(string str)
    {
        if (str == null || str.Length <= 1)
        {
            return str;
        }

        StringBuilder revStr = new StringBuilder(str.Length);

        for (int count = str.Length - 1; count > -1; count--)
        {
            revStr.Append(str[count]);
        }
        return revStr.ToString();
    }

    public static void Main()
    {
        Console.WriteLine(ReverseString("The quick brown fox jumped over the lazy dog."));
    }
}