Re: do { quit; } else { }

On 09/04/2025 11:00, Ike Naar wrote:

On 2025-04-08, bart <bc@freeuk.com> wrote:

However if I need to initialise the variable:
>
     extern int table[];          // shared
     int table[] = (10, 20, 30)
>
then other modules can't pick up length of the array.

    extern int table[3];

That is fine if you know the size in advance of initialisation.  Very often, of course, you /do/ know the size - especially when talking about data shared directly between translation units.  (And if it is not shared, you don't declare it in a header.)
An array really needs two bits of information - a way to find the first element, and the number of elements.  (There are also other bits of compile-time data such as the type.)  In C, these two things are not tightly joined - you typically have to pass them separately when exchanging information about an array.  This means you get maximal efficiency - you don't need to pass around information that you have no use of or know from somewhere else.  But it also means you need a little extra effort in the code when you need them both.
For example, you can have :
// unit.h
extern int table[];
extern const int table_count;
// unit.c
#include "unit.h"
int table = [10, 20, 30};
const int table_count = sizeof(table) / sizeof(table[0]);