Reverse a number

Use it to reverse a given number. Data types are declared as BigIntegers to use this function to find a palindrome given a number.


BigInteger is available in .NET Framework 4.  


You need a reference to  System.Numerics name space to use this datatype.

private BigInteger ReverseNumber(BigInteger n)
        {
            BigInteger left = n;
            BigInteger rev = 0;
            BigInteger r;
            while (left > 0)
            {
                r = left % 10;
                rev = rev * 10 + r;
                left = left / 10;  //left = Math.floor(left / 10); 
            }


            return rev;


        }




If you wish to read a number as a string, the following would be helpful.



 public static string ReverseString(string s)
        {
            char[] arr = s.ToCharArray();
            Array.Reverse(arr);
            return new string(arr);
        }