hex to string problems

I'v got this got to work for binary and deciaml by change it to a 2 or a 10 for the base, but when I use 16 for Hex, it doesn't produce the correct results for some reason. Any ideas?

Code:

---

if(base =='h')
{
        int temp = x, quotient, remainder;
        int count = 0;
        int i;
        int p;
        int q;

        do{
                quotient = temp/16;  //base
                temp = quotient;
                count++;
        }
        while(quotient != 0);

        count++;
        temp = x;
        //char *aray = new char[count];

        for(p=0, q=count-2; p<count-1; p++, q--)
        {
                quotient = temp / power(16, q); //base
                remainder = temp % (int)power(16, q);  //base
                string[p] =  quotient+48;
                temp = remainder;
        }
        string[p] = 0;//giving null character to last element of aray.
        return x;
}

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Quote:

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Originally Posted by ERIKh22a

I'v got this got to work for binary and deciaml by change it to a 2 or a 10 for the base, but when I use 16 for Hex, it doesn't produce the correct results for some reason. Any ideas?

---

Do you know why this works for bin and dec ascii digits?

Code:

---

  string[p] =  quotient+48;

---

ASCII '0' = decimal 48
ASCII '1' = decimal 49


etc.

but if you want ascii chars for 'a' - 'f' or 'A' - 'F', you have to do a little more work (not much)

Perhaps you can make a function that returns the ASCII char for all integers from 0 - 15. Call it, say, decimal_hex_value_to_ascii_char(), or something. Then do this:

Code:

---

  string[p] =  decimal_hex_value_to_ascii_char(quotient);

---

Regards,

Dave

Quote:

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Originally Posted by Dave Evans

Do you know why this works for bin and dec ascii digits?

Code:

---

  string[p] =  quotient+48;

---

ASCII '0' = decimal 48
ASCII '1' = decimal 49


etc.

---

Of course, that's non-portable. ;)

Quzah.

Quote:

---

Originally Posted by Dave Evans

Do you know why this works for bin and dec ascii digits?

Code:

---

  string[p] =  quotient+48;

---

ASCII '0' = decimal 48
ASCII '1' = decimal 49


etc.

but if you want ascii chars for 'a' - 'f' or 'A' - 'F', you have to do a little more work (not much)

Perhaps you can make a function that returns the ASCII char for all integers from 0 - 15. Call it, say, decimal_hex_value_to_ascii_char(), or something. Then do this:

Code:

---

  string[p] =  decimal_hex_value_to_ascii_char(quotient);

---

Regards,

Dave

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Something liek this

Code:

---

string[p] =  hexa(quotient);




int hexa( char hex )


        {
        switch(hex ) {
        case 'F':
        case 'f': return( 15);
        case 'E':
        case 'e': return( 14);
        case 'D':
        case 'd': return( 13);
        case 'C':
        case 'c': return( 12);
        case 'B':
        case 'b': return( 11);
        case 'A':
        case 'a': return( 10);
        case '9': return( 9);
        case '8': return( 8);
        case '7': return( 7);
        case '6': return( 6);
        case '5': return( 5);
        case '4': return( 4);
        case '3': return( 3);
        case '2': return( 2);
        case '1': return( 1);
        default: return( 0);
                }

---

Or how about...

Code:

---

int hex_to_int(char hexnum)
{
  char array[] = "0123456789abcdef";
  char *ptr;

  if((ptr = strchr(array, tolower(hexnum))))
    return ptr - array;

  return 0;
}

---

Quote:

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Originally Posted by itsme86

Or how about...

Code:

---

int hex_to_int(char hexnum)
{
  char array[] = "0123456789abcdef";
  char *ptr;

  if((ptr = strchr(array, tolower(hexnum))))
    return ptr - array;

  return 0;
}

---

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Any other ideas? I couldn't get it to implement..

What problem did you have implementing it? Looks pretty simple to me.

As an aside though, I would have the function return -1 on error instead of 0. Otherwise there isn't any way to distinguish between an error or if "0" is passed.

I can only get it to print out numbers 10-15

Quote:

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Originally Posted by bithub

What problem did you have implementing it? Looks pretty simple to me.

As an aside though, I would have the function return -1 on error instead of 0. Otherwise there isn't any way to distinguish between an error or if "0" is passed.

---

Code:

---

if(base =='h')
{
  int temp = x, quotient, remainder;
  int count = 0;
  int i;
  int p;
  int q;

  do
      {
      quotient = temp/16;
      temp = quotient;
      count++;
      }while(quotient != 0);

  count++;
  temp = x;

  for(p=0, q=count-2; p<count-1; p++, q--)
      {
      quotient = temp / power(16, q);
      remainder = temp % (int)power(16, q);
      string[p] =  hexa(quotient);
      temp = remainder;
      }

  string[p] = 0;

  return x;
}

int hexa(char hex)
{
        if(hex <10)
        return hex;
else

        if (hex == 10)
        return 'A';
        if (hex == 11)
        return 'B';
        if (hex == 12)
        return  'C';
        if (hex == 13)
        return 'D';
        if (hex == 14)
        return  'E';
        if (hex == 15)
        return 'F';

return 0;
}

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Nevermind got it to work