Calculating the number of bits in a Subnet Mask in C#

Question

I have a task to complete in C#. I have a Subnet Mask: 255.255.128.0.

I need to find the number of bits in the Subnet Mask, which would be, in this case, 17.

Answer 1

You can convert a number to binary like this:

        string ip = "255.255.128.0";
        string[] tokens = ip.Split('.');
        string result = "";
        foreach (string token in tokens)
        {
            int tokenNum = int.Parse(token);
            string octet = Convert.ToString(tokenNum, 2);
            while (octet.Length < 8)
                octet = octet + '0';
            result += octet;
        }
        int mask = result.LastIndexOf('1') + 1;