How to determine the length of an array at compile time?

Question

Are there macros or builtins that can return the length of arrays at compile time in GCC?

For example:

int array[10];

For which:

Answer 1

    sizeof(array) / sizeof(int) 

Answer 2

(sizeof(array)/sizeof(array[0]))

Or as a macro

#define ARRAY_SIZE(foo) (sizeof(foo)/sizeof(foo[0]))

    int array[10];
    printf("%d %d\n", sizeof(array), ARRAY_SIZE(array));

40 10

Caution: You can apply this ARRAY_SIZE() macro to a pointer to an array and get a garbage value without any compiler warnings or errors.

Answer 3

im not aware of a builtin that does this, but i recently used:

sizeof(array)/sizeof(array[0])

to do just that

Answer 4

I wouldn't rely on sizeof since aligment stuff could mess up the thing.

#define COUNT 10
int array[COUNT];

And then you could use COUNT as you want.