以C语言中的printf方式转换无符号字符

Question

I have an unsigned char that I want to convert to hexadecimal. I know printf("%02X", char) gives me the output I want, but it is sent to the terminal and is thus of little use. How can I convert the character to hexadecimal and store it in a variable the same way printf does it?

Answer 1

How about something like:

stringstream ss;
ss << std::hex << std::setw(2) << (unsigned int) x;

cout << ss.str() << endl;

You might want to tweak the stringstream some more though.

Answer 2

Use sprintf instead into a buffer, for example

char str[50];
sprintf(str, "%X02", char);

Answer 3

Maybe the fastest one?

struct hex_uchar {
   hex_uchar(unsigned char c)
   {
      value[0] = hc[c >> 4];
      value[1] = hc[c & 0xF];
      value[2] = '\0';
   }
   char value[3];
   static char hc[16];
};
char hex_uchar::hc[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
                           'A', 'B', 'C', 'D', 'E', 'F' }; 


int main() {
   std::cout << hex_uchar('A').value << std::endl;
}

Answer 4

Pay attention: you are not converting it to hex value, you are converting to a null terminated string. Store it in a variable of your model is kind of nonsense.