Convert binary format string to int, in C

Question

How do I convert a binary string like \"010011101\" to an int, and how do I convert an int, like 5, to a string \"101\" in C?

Answer 1

If it is a homework problem they probably want you to implement strtol, you would have a loop something like this:

char* start = &binaryCharArray[0];
int total = 0;
while (*start)
{
 total *= 2;
 if (*start++ == '1') total += 1;
}

If you wanted to get fancy you could use these in the loop:

   total <<= 1;
   if (*start++ == '1') total^=1;