Thread: Not sure where to begin

This is what I have in my .c file

Code:

#include <stdio.h> 
#include "intgetnum.h"
#define MAXNUM 2
/* prototype */
int getnum();
int main()
{
  int retval = 1;
  while (retval != NULL)
    {
      retval = getnum();
    }
  printf("The number was %d\n", retval);
  return 0;
}

this is what is in my header files

Code:

/* Declarations */
int getnum()
{
  int ch;
  int null;
  int pos = 0;
  int nflag = 0;
  int number = 0;

  if (pos == 0)
  {
    printf("Enter two numbers\n", pos++);
    scanf("%d", &number);
  }
  if (ch == '+')
    {
      pos++;
    }
  if (ch == '-')
    {
      nflag=1;
    }
  if (ch >= 48 && ch <= 57)
    {
      number *= 10;
      pos++;
    }

  if (nflag == 1)
    {
      number *= -1;
    }

  if (ch = ' ' || ch == '\n')
  {
  
  }
  else
    {
      return null;
    }

}

Originally Posted by sl4nted

header files are not for functions.
add it all to one file

getnum only returns if ch != ' ' and ch != '\n' (ch is uninitialized for all your tests on it)
and it returns an uninitialized value

you ask the user to enter 2 numbers but are only trying to capture 1 of them

what is the program supposed to do?...so we have a better idea of what your trying to accomplish

It's suppose to just echo back the two numbers the user enters. For practice, and this is how I was told to do it, to put the functions into the header file.

this is how I was told to do it, to put the functions into the header file.

who told you that, I doubt they meant the actual function, maybe the prototype

nope, and I didn't say it wouldn't work, I said thats not what header files are for.

whats all the other stuff for if you just want to echo the 2 integers?

scanf("%d", &number);
will only get 1 of them

edit::
again I didn't say ch != is what you want I said
"getnum only returns if ch != ' ' and ch != '\n' "
please read a bit more carefully the answers are there

Originally Posted by sl4nted

nope, and I didn't say it wouldn't work, I said thats not what header files are for.

whats all the other stuff for if you just want to echo the 2 integers?

scanf("%d", &number);
will only get 1 of them

edit::
again I didn't say ch != is what you want I said
"getnum only returns if ch != ' ' and ch != '\n' "
please read a bit more carefully the answers are there

I fixed that part, it runs, it's just that my value keeps coming back as 0

null is not initialized
int null = 1; for example

and you need a return outside of that else block, because if ch is space or enter, it doesn't return ::edit echoes

Originally Posted by sl4nted

null is not initialized
int null = 1; for example

and you need a return outside of that else block, because if ch is space or enter, it doesn't return ::edit echoes

Cool thanks, i'm almost there, now I know it's the null, I assigned 1 to null but now it just loops with no value hmmm

because retval is never NULL

getnum only returns 1
since you've set
null = 1

null is not the same as NULL

Code:

while (retval != NULL)

Code:

return null;

Code:

#include <stdio.h> 
#include "intgetnum.h"
#define MAXNUM 2
/* prototype */
int getnum();
int main()
{
  int retval = 1;
  while (retval != NULL)
    {
      retval = getnum();
    }
  printf("The number was %d\n", retval);
  return 0;
}

Code:

/* Declarations */
int getnum()
{
  int pos = 0;
  int nflag = 0;
  int number = 0;
  int num1, num2;
  char ch;
  ch=getchar();
    
  printf("Enter your first numbers\n");
  scanf("%d", &num1);
  printf("Enter your second number\n");
  scanf("%d", &num1);

  if (pos == 0)
  {
    pos++;  
  }
  if (ch == '+')
    {
      pos++;
    }
  if (ch == '-')
    {
      nflag=1;
    }
  if (ch >= 48 && ch <= 57)
    {
      number *= 10;
      ch = 48;
      pos++;
      ch=getchar();
    }

  if (nflag == 1)
    {
      number *= -1;
    }

  if (ch == ' ' || ch == '\n')
    {
    }
    else

    return NULL;

}

I still get a infinate loop, unless i press a letter a few times, then I get a return value of 0