I needed a way to convert a string of bits to a byte array: string -> byte[]

For example take the string 101100110010001111
I need my byte[] to contain: 10001111b (143d), 11001100b (204d), 10b (2d)

I saw a bunch of solutions to this problem in this post but they were either inadequate or too complex for all possible scenarios.

I decided to try to devise my own solution:

        private static byte[] getBitwiseByteArray(string input)
        {
            List<byte> byteList = new List<byte>();
            for (int i = input.Length - 1; i >= 0; i-=8)
            {
                string byteString = "";
                for (int j = 0; (i - j) >= 0 && j < 8; j++)
                {
                    byteString = input[i - j] + byteString;
                }
                if (byteString != "")
                {
                    byteList.Add(Convert.ToByte(byteString, 2));
                }
            }
            return byteList.ToArray();
        }

Let’s take an example (for easy visualization of the logic): 101100110010001111

I need to first extract 8 bits at a time from right to left. Therefore my i iterator counts down from the end of the string to the beginning in sets of 8.

After extracting, I should get 10001111, 11001100, 10

The j iterator ensures that I don’t take more than 8 bits at a time. It also ensures that when there are less than 8 bits left in the string (as in the case of 10 where only 2 bits were left), I stop extracting at that stage.

byteString contains at most 8 bits and is ready to be converted to a byte type using the Convert.ToByte function with the binary format specified.