A convert back from the given string into byte/sbyte

Question

I have a function which form a string like this

public static string formString(sbyte myByte)
{
   try
   {
      var str = string.Empty;
      for (int i = 0; i <= 7; i++)
      {
         if(( (1<<i) & myByte ) == 0)
         {
            str = str + "0";
         }
         else
         {
            str = str + "1";
         }
      }
      return str;
   }
   catch (System.Exception ex)
   {
      return null;
   }
}

In this way, if I put a sbyte like(9), then the string result will be "10010000" , so here's the question , how can I just convert string "10010000" back to the given sbyte?

just wanted to show the sbyte into a string like this which means "0" false, "1" true in 8 chars; — Cagaya Coper, Nov 05 '16 at 08:01
why not doing myByte.ToString(), because 10010000 is not equivalent to 9 — Vivek Nuna, Nov 05 '16 at 08:02
it's in reverse so the string is "00001001" I just wanted to convert it back to 9 — Cagaya Coper, Nov 05 '16 at 08:06

score 1 · Answer 1 · answered Nov 05 '16 at 08:03

1

You probably know how binary works. They are 2^0+2^1+2^2+2^3+.... So when the string is 10010000, you can just set the result as 2^0+2^3. I think your output binary string are in reverse order. The string should be 00001001, you should put the high bit in front of the string and low bit at the back of string. Because the first bit is 1 so the result add 2^0, and the forth element is 1 so the result should add by 2^3. And then you get the result.

answered Nov 05 '16 at 08:03

RavlueReference

75
9

yes the string is just in reverse, so when I convert back , the string should be "00001001", but I do not know how to convert the "00001001" back to sbyte, I think sbyte.parse would not help – Cagaya Coper Nov 05 '16 at 08:05
0 0 0 0 1 0 0 1 – RavlueReference Nov 05 '16 at 08:07
7 6 5 4 3 2 1 0 <- This is the bit order of binary digit. – RavlueReference Nov 05 '16 at 08:08
Because only bit number No. 3 and bit No. 0 is 1, so the result should be 2^0 + 2^3. You can get more information about binary conversion through Google. – RavlueReference Nov 05 '16 at 08:10
string input = "00001001"; int res = 0; for (int i = input.Length - 1; i > 0; i--) { if (input[i] == '1') { res += (int)Math.Pow(2, input.Length - 1 - i); } } Console.WriteLine(res); – RavlueReference Nov 05 '16 at 08:17

score 1 · Accepted Answer · answered Nov 05 '16 at 08:17

1

string str = "10010000";
str = (str.TrimEnd('0', '\0'));
sbyte s = Convert.ToSByte(str, 2);

First remove all the trailing zeros from string and then convert to sbyte with base 2. It will give you back 9.

answered Nov 05 '16 at 08:17

Vivek Nuna

25,472
25
109
197

Thanks I just found the answer, lol , also thanks this just works! – Cagaya Coper Nov 05 '16 at 08:26

A convert back from the given string into byte/sbyte

2 Answers2