#define array[]

[cs05pp2]

Hello. I have a problem. I want to define a constant array.

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

#define array[] {'a', 'b', 'c'}


int main()
{
  system("clear");

  printf("\n\n%c\n\n", array[0]);

  return 0;
}

when I try to compile with gcc I get that error

p.c:4:13: warning: missing whitespace after the macro name
p.c: In function 'main':
p.c:11: error: syntax error before '[' token


Any one who knows how to define a constant array? Pleace help? Thank you.

[Epy]

does const not work?

[anon]

This expands to

printf("\n\n%c\n\n", [] {'a', 'b', 'c'}[0]);

What did you expect?

[quzah]

This expands to

No, it would only expand to that if there was a space after the word array. As-is, it just fails to compile.


Quzah.

[anon]

Interestingly with GCC it only deserves a warning, with Comeau Online it is an error in C99 mode and a warning in C90 mode.

[cpjust]

Any one who knows how to define a constant array? Pleace help? Thank you.

const char array[] = "abc";

[cs05pp2]

If I use that code is working and compile:

int main()
{
int array[] = {1,2,3,4,5};

printf("%d", array[0]);

return 0;
}

but if I try to define it as constant I get an error from the gcc compiler.

#define array[] {1,2,3,4,5};
int main()
{


printf("%d", array[0]);

return 0;

How can I define a constant array ? Thank you

[King Mir]

An array requires a physical location in memory. It cannot be implemented as a simple macro. cpjust's code is the correct way to do this.

[cs05pp2]

If I define

#define array "abcdef"

int main()
{
printf("%c", array[0]);

return 0;
}

It will work, and the string is an array of characters. So I still believe that I can define a constant array. But I don't know how.

[laserlight]

It will work, and the string is an array of characters. So I still believe that I can define a constant array. But I don't know how.

Right, but then "abcdef"[0] is valid syntax. Suppose that you did not define a macro. How would you do what you are trying to do? If you cannot do it, then you cannot do it by defining a macro, since preprocessing would result in textual substitution.

[whiteflags]

#define array "abcdef"

it only works because "abcdef" is a string literal. There are no other "literal" arrays in C, they should have a proper identifier. If you think that #define makes an identifier out of some phrase, then please review what your text says about the prepocessor: you are wrong.

[cas]

It can be done in C99 (look up compound literals); but I can't see much of a reason to do so when you can just use const, which is portable to non-C99 compilers.

The real question is, why are you hell-bent on avoiding the creation of an array and tagging it with const?