How to get the Nth digit of an integer with bit-wise operations?

Question

Example. 123456, and we want the third from the right (\'4\') out.

The idea in practise is to access each digit seperately (ie. 6 5 4 3 2 1).

C/C++/C# preferred.

Answer 1

Just spent time writing this based on answers here, so thought I would share.

This is based on Brannon's answer, but lets you get more than one digit at a time. In my case I use it to extract parts from a date and time saved in an int where the digits are in yyyymmddhhnnssm_s format.

public static int GetDigits(this int number, int highestDigit, int numDigits)
{
    return (number / (int)Math.Pow(10, highestDigit - numDigits)) % (int)Math.Pow(10, numDigits);
}

I made it an extension, you might not want to, but here is sample usage:

int i = 20010607;
string year = i.GetDigits(8,4).ToString();
string month = i.GetDigits(4,2).ToString();
string day = i.GetDigits(2,2).ToString();

results:

year = 2001

month = 6

day = 7