basic #define usage

[Kelly]

Hi,

Ashamed to ask basic question but I cannot get this code to run,

#define Y one

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (void) {
//Y=malloc(sizeof(char *));
printf ("%s",Y);

return 0;

}

I can compile but not run, gives me "the memory cannot be read".
All I want is to printf Y.

Please help, I know this is easy for most of you.

Thanks.
Kel

 

[Ben Pfaff]

#define Y one

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (void) {
//Y=malloc(sizeof(char *));
printf ("%s",Y);

return 0;

}

Y expands to one.
one is undefined.
This won't compile.

 

[Martin Ambuhl]

Hi,

Ashamed to ask basic question but I cannot get this code to run,

#define Y one

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (void) {
//Y=malloc(sizeof(char *));
printf ("%s",Y);

return 0;

}

I can compile but not run, gives me "the memory cannot be read".
All I want is to printf Y.

Please help, I know this is easy for most of you.

It's easy for anyone who checks the FAQ before posting.
Below is a version of your program which shows various behaviors that you
might one to check. The question and answer in the FAQ can be found at
<http://www.eskimo.com/~scs/C-faq/q11.17.html>

#define Y one
#define Z "one"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define STR_aux(x) #x
#define STR(x) STR_aux(x)

int main(void)
{
printf("%s\n", STR_aux(Y));
printf("%s\n", STR(Y));
printf("%s\n", STR_aux(Z));
printf("%s\n", STR(Z));
printf("%s\n", Z);
return 0;
}

[output]
Y
one
Z
"one"
one

 

[Jeff]

Hi,

Ashamed to ask basic question but I cannot get this code to run,

#define Y one

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (void) {
//Y=malloc(sizeof(char *));
printf ("%s",Y);

return 0;

}

I can compile but not run, gives me "the memory cannot be read".
All I want is to printf Y.

Please help, I know this is easy for most of you.

Try #define Y "one"