Is this possible in c?

Question

int fun(int a[22]);

Answer 1

yes it is.

but you should know that an array type is passed into a function as a pointer to the first element of the array, you can use array notation (int[]) or pointer notation (int*) in the function declaration, the compiler always treats it as pointer (int*). for example, the following declarations are equivalent:

int fun(int a[22]);
int fun(int *a);
int fun(int a[]);

they will be treated as int* by the compiler, as follow. the size of the array given in [] is ignored.

Answer 2

And what is it supposed to do?

Answer 3

It is a prototype