Thread: about decimal to hex progam

hi everyone,

I am trying to implement a program that converts a decimal into
Hex, I am having some problem it doesn't do the right computation, can anyone see any abnormality of my implementaion.

Here is the code:

Code:

code
/* this function decimal number and transforms into hex */
char HexConvert(int val)
{
     char  *iter = val+10;
     
    
    while(iter>=val+2){
      /*compute hex digit*/
      if(val)
      {
          *iter = val%16;
          val/=16;
        
          if(*iter<10) /*output integer*/
          *iter+='0';
          return iter;
          else         /*output character*/
          *iter+=55; /* ASCII Value for A (=10) is 65 (=55+10) */
          return iter; 
      }
      else /*fill remaining hex array with zeros*/
        *iter = '0';
         return iter;
      iter--;

   }

You have some problems with iter, because it points to a relatively random memory location with the address of val's content + 10.
Also, there's actually no need for an if-test, just try something like;

Code:

#include <stdio.h>

int main()
{
  char buf[11],
       buf2[11],
       i = 0,
    j;
  int val = 255;
  while( val )
    buf[i] = "0123456789ABCDEF"[ val % 16 ], val /= 16, ++i;
  buf[i] = 0;
  for( i -= 1, j = 0; i > -1; i--, j++ )
    buf2[j] = buf[i];
  buf2[j] = 0;
  puts( buf2 );
  return 0;
}

Code:

int a=10;/*decimal*/
printf("%d in hexadecimal is %x\n",a,a);