return array in c

1// fill a preallocated buffer provided by 
2// the caller (caller allocates buf and passes to the function)
3void foo(char *buf, int count) {
4    for(int i = 0; i < count; ++i)
5        buf[i] = i;
6}
7
8int main() {
9    char arr[10] = {0};
10    foo(arr, 10);
11    // No need to deallocate because we allocated 
12    // arr with automatic storage duration.
13    // If we had dynamically allocated it
14    // (i.e. malloc or some variant) then we 
15    // would need to call free(arr)
16}

1void return_array(char *arr, int size) {
2    for(int i = 0; i < size; i++)
3        arr[i] = i;
4}
5
6int main() {
7  	int size = 5;
8    char arr[size];
9    return_array(arr, size);
10}