Errors in this function, dont know why

I need help, I wrote this piece of function and try to compile with gcc this code and it gives me errors like this, I am new at c language still trying to get used to it, any help or suggestions are much appreciated . thanks in advance

1- error: ‘YES’ undeclared (first use in this function) inhex = YES;
2- note: each undeclared identifier is reported only once for each function it appears in
error: ‘NO’ undeclared (first use in this function)
inhex = NO;

Code:

---

int xtoi (char hexstring[]){


  int hexdigit, i, inhex, n;
  i=0;


  if(hexstring[i] == '0') {
    ++i;
    if(hexstring[i] == 'x' || hexstring[i] == 'X') {


      ++i;
    }
 }


  n = 0;
  inhex = YES;
  for(; inhex == YES; ++i) {
    if(hexstring[i] >= '0' && hexstring[i] <= '9') {
      hexdigit = hexstring[i] - '0';
    }else if(hexstring[i] >= 'a' && hexstring[i] <= 'f') {
      hexdigit = hexstring[i] - 'a' + 10;
    }else if(hexstring[i] >= 'A' && hexstring[i] <= 'F') {
      hexdigit = hexstring[i] -'A' + 10;
    }else{
      inhex = NO;


    }

---

Quote:

---

Originally Posted by erald23

1- error: ‘YES’ undeclared (first use in this function) inhex = YES;
2- note: each undeclared identifier is reported only once for each function it appears in
error: ‘NO’ undeclared (first use in this function)
inhex = NO;

---

That's exactly what it says: you didn't declare the identifiers named YES and NO. Perhaps you should just use 1 and 0 instead, or true and false if you #include <stdbool.h>.

I did as you suggested I put DEFINE YES 1, DEFINE NO 0, and the errors are fixed, but I'm having another error in my void function like this

expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘void’
void itox (char hexstring[], int n)

That means that you have a syntax error. If you want me to elaborate, you would need to elaborate with the relevant code. I suggest posting the smallest and simplest program that you expect should compile but which demonstrates this error.

/* trying to convert integer to hexa */
even other suggestion to shrink down it would be appreciated I feel like is too messy like this

Code:

---

#include <stdio.h>
#include <string.h>
#include "xbits.h"
#define YES 1
#define  NO  0


void itox (char hexstring[], int n)
  printf("in itox, processing %d\n", n);
{
  char hexdigit[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
  int index = 0;
  int remain;


  while(n > 0) {
  remain = n%16;
  n/=16;
  hexstring[index++] = hexdigit[remain];
}


  hexstring[index] = '\0';
  printf("decimal: %d\thexstring %s\n", n, hexstring);


}

---

Notice that you wrote the first printf call before the opening brace for the definition of the itox function.

I did delete printf and now is duplicated the error.

Code:

---

expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘void’
void itox (char hexstring[], int n)
^
error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
{
^
error: expected ‘{’ at end of input
}

---

[


QUOTE=laserlight;1280074]Notice that you wrote the first printf call before the opening brace for the definition of the itox function.[/QUOTE]

Quote:

---

Originally Posted by erald23

I did delete printf and now is duplicated the error.

---

Look, it is good that you post the error messages, but you have to post the code too. If you made a change in response to help, post the updated code along with the new error message. Make another change in response to help, post the newly updated code with the latest error message.

I deleted the printf and your unnecessary includes and #define statements and I find that there is not even a warning:

Code:

---

#include <stdio.h>


void itox (char hexstring[], int n)
{
  char hexdigit[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
  int index = 0;
  int remain;


  while(n > 0) {
  remain = n%16;
  n/=16;
  hexstring[index++] = hexdigit[remain];
}


  hexstring[index] = '\0';
  printf("decimal: %d\thexstring %s\n", n, hexstring);


}

int main(void)
{
    return 0;
}

---

So what gives? Obviously, you made a mistake, but we already knew that, and even now I cannot tell you what mistake you made because I don't know what's your current code.

ok so this program has two functions the first one"void itox" converts interger to hexastring and second one 'int xtoi" converts hexstring to its own value.

The whole code I have is this and I'm having problems compiling

Code:

---

#include <stdio.h>
#include <string.h>
#include "xbits.h"
#define YES 1
#define  NO  0






 /* function converts int n to a hexstring  */


void itox (char hexstring[], int n)


{
  char hexdigit[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E\
','F'};
  int index = 0;
  int remain;
  printf("in itox, processing %d\n", n);
  while(n > 0) {
  remain = n%16;
  n/=16;
  hexstring[index++] = hexdigit[remain];


}


  hexstring[index] = '\0';
  printf("decimal: %d\thexstring %s\n", n, hexstring);


}




 /* converts a hexstring to its int  */
int xtoi (char hexstring[])
{


  int hexdigit, i, inhex, n;
  i=0;


  if(hexstring[i] == '0') {
    ++i;
    if(hexstring[i] == 'x' || hexstring[i] == 'X') {

---

Code:

---

int xtoi (char hexstring[]){


  int hexdigit, i, inhex, n;
  i=0;


  if(hexstring[i] == '0') {
    ++i;
    if(hexstring[i] == 'x' || hexstring[i] == 'X') {


      ++i;
    }
 }


  n = 0;
  inhex = YES;
  for(; inhex == YES; ++i) {
    if(hexstring[i] >= '0' && hexstring[i] <= '9') {
      hexdigit = hexstring[i] - '0';
    }else if(hexstring[i] >= 'a' && hexstring[i] <= 'f') {
      hexdigit = hexstring[i] - 'a' + 10;
    }else if(hexstring[i] >= 'A' && hexstring[i] <= 'F') {
      hexdigit = hexstring[i] -'A' + 10;
    }else{
      inhex = NO;


    }
    if(inhex == YES) {
      n = 16 * n+ hexdigit;
    }


  }

return n;
}

---

errors are

Code:

---

error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘void’ void itox (char hexstring[], int n)
 ^
error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
 {
 ^
 error: expected ‘{’ at end of input
 }

---

Is this all in a single file? It looks like you made a typo error such that you ended up with two code blocks. Combining them:

Code:

---

#include <stdio.h>
#include <string.h>
/*#include "xbits.h"*/

#define YES 1
#define  NO  0


/* function converts int n to a hexstring  */
void itox (char hexstring[], int n)
{
    char hexdigit[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    int index = 0;
    int remain;
    printf("in itox, processing %d\n", n);
    while(n > 0) {
        remain = n%16;
        n/=16;
        hexstring[index++] = hexdigit[remain];
    }

    hexstring[index] = '\0';
    printf("decimal: %d\thexstring %s\n", n, hexstring);
}


int xtoi (char hexstring[])
{
    int hexdigit, i, inhex, n;
    i=0;

    if(hexstring[i] == '0') {
        ++i;
        if(hexstring[i] == 'x' || hexstring[i] == 'X') {
            ++i;
        }
    }

    n = 0;
    inhex = YES;
    for(; inhex == YES; ++i) {
        if(hexstring[i] >= '0' && hexstring[i] <= '9') {
            hexdigit = hexstring[i] - '0';
        }else if(hexstring[i] >= 'a' && hexstring[i] <= 'f') {
            hexdigit = hexstring[i] - 'a' + 10;
        }else if(hexstring[i] >= 'A' && hexstring[i] <= 'F') {
            hexdigit = hexstring[i] -'A' + 10;
        }else{
            inhex = NO;
        }
        if(inhex == YES) {
            n = 16 * n+ hexdigit;
        }
    }

    return n;
}


int main(void)
{
    return 0;
}

---

I still don't see any compile error. Notice that I commented out the include of "xbits.h" though, which you apparently don't need. Perhaps the error lies there, but you shouldn't be including header files that you don't need.

Also, notice that I indented your code properly.

sorry I should've said that we are using a driver in a separate file and execute them together on emacs to combine them, I'm still working on it and is like this

Code:

---

#include <stdio.h>#include <string.h>
#include "xbits.h"


#define ENOUGH_SPACE (sizeof(int) * 2 + 1)
#define LINELEN      1024


int main(void)
{
  char hexstring[ENOUGH_SPACE], line[LINELEN];
  int m, n;


  /*loop                                                                                                                               
  * use fgets(line, LINELEN, stdin) to read from keyboard                                                                             
  * stop the loop if EOF                                                                                                               
  * use sscanf(line, "%d", &n) to convert input to int n                                                                               
  */
  while  (( fgets(line, LINELEN, stdin) != NULL ) {


    scanf(line, "%d", %n);
          printf("%d\n" %n);


  itox(hexstring, n);
  m = xtoi(hexstring);
  printf("\ninput decimal int  : %d\n", n);
  printf("hex representation  : %s\n", hexstring);
  printf("reconverted decimal : %d\n\n", m);


    }
  return 0;

---

Quote:

---

Originally Posted by erald23

sorry I should've said that we are using a driver in a separate file and execute them together on emacs to combine them, I'm still working on it and is like this

---

You desperately need to format your code properly, especially regarding indentation. Here's what you posted with proper indentation:

Code:

---

#include <stdio.h>
#include <string.h>
#include "xbits.h"


#define ENOUGH_SPACE (sizeof(int) * 2 + 1)
#define LINELEN      1024


int main(void)
{
    char hexstring[ENOUGH_SPACE], line[LINELEN];
    int m, n;


    /*loop
    * use fgets(line, LINELEN, stdin) to read from keyboard
    * stop the loop if EOF
    * use sscanf(line, "%d", &n) to convert input to int n
    */
    while  (( fgets(line, LINELEN, stdin) != NULL ) {
        scanf(line, "%d", %n);
        printf("%d\n" %n);

        itox(hexstring, n);
        m = xtoi(hexstring);
        printf("\ninput decimal int  : %d\n", n);
        printf("hex representation  : %s\n", hexstring);
        printf("reconverted decimal : %d\n\n", m);
    }

    return 0;

---

Can you spot the mistake now?