Thread: Standard alternative to sizeof(array)/sizeof(array[0])?

Is there a good standard alternative to the

Code:

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

used for determining the size of an array?

Well sometimes you see:

Code:

sizeof array/sizeof*array

but this is only somewhat shorter and not hardly better.

What I'm looking for is a standard macro in a standard header, something like

Code:

#define lenof(a) (sizeof(a)/sizeof((a)[0]))

but there is no such thing in stddef.h where offsetof is defined.
There is the further problem, that

Code:

int foo(short array[8]) 
{
   return lenof(array);
}

will return 2 not 8 on most targets, due to the fact that foo is equal to

Code:

int foo(short *array)

which is a rather obscure feature of C.

Originally Posted by Salem

> which is a rather obscure feature of C.
Nope - that's the perfectly normal behaviour of C.

Well the 'obscure' thing is that C accepts

Code:

int foo(short bar[8])

even as the number is redundant and unused. As the compiler does not care about the size of the array it shall insist on omitting it and complain on anything but:

Code:

int foo(short bar[])

Originally Posted by claudiu

There is a difference though between:

int foo(short bar[])

and

int foo(short *bar)

Cprogramming.com FAQ > Pointers And Arrays (intermediate)

No there is no difference in this case, as correctly stated in the FAQ:

Rule 3:
An array name in the declaration of a function parameter is
treated by the compiler as a pointer to the first element of the array.