Thread: boolean.c

Hi I am having problems compiling this program they are 3 errors in line 7. Can you help me find the problem?

Thanks for your help.

boolean.c(7) : error C2065: 'Bool' : undeclared identifier
boolean.c(7) : error C2146: syntax error : missing ';' before identifier 'input_is_good'
boolean.c(7) : error C2065: 'input_is_good' : undeclared identifier
Error executing cl.exe.

Code:

// boolean.c -- using a _Bool variable
#include <stdio.h>
int main(void)
{
  long num;
  long sum = 0L;
  _Bool input_is_good;  //where the error is
  printf("Please enter an integer to be summed. ");
  printf("Enter q to quit.\n");
  input_is_good = (scanf("%ld", &num) == 1);
  while (input_is_good)
  {
        sum = sum + num;
        printf("Please enter next integer to be summed. ");
        printf("Enter q to quit.\n");
        input_is_good = (scanf("%ld", &num) == 1);
  }
  printf("Those integers sum to %ld.\n", sum);
  return 0;
}

it says _Bool does not exist, perhaps it is capitalized differently.

To use _Bool you need to include the appropriate header and have a C99 compiler. _Bool is in stdbool.h.


Quzah.

>_Bool is in stdbool.h.
_Bool is a data type in C99, you don't need to include any headers. You do need to include stdbool.h to get the bool, true, and false macros though.

You're trying to compile c99 on a microsoft compiler and microsoft compilers don't support c99. Perhaps you should consider getting yourself a compiler which does, such as MinGW (Dev-cpp, code::blocks are popular ides for this).

>>stdbool.h <<

Microsoft compilers don't have stdbool.h(msvc7 and msvc8 don't).

I learn something today. I was running it on a windows compiler visual studio c++ 6.0 but it didint work as you said the compiler didint support it. When i ran the program on a linux compiler gcc works perfect.

Thanks and have a nice day

>Or you could use BOOL (C compiler) or bool (C++ compiler) instead if you want it to compile on Windows.
Or you could use an unsigned char, get the same effect, and have it compile everywhere.