Question

I want to pass an array of long long to an objective c function. I would like the array to be passed as a pointer, if possible, so that copying is not done. I wrote this code:

+ (int) getIndexOfLongLongValue: (long long) value inArray: (long long []) array size: (int) count
{
    for (int i =0; i < count; i++)
    {
       if (array[i] == value)
           return i + 1;
    }
    return 0;
}

to which I pass

long long varname[count];

as the second argument. I am wondering if I can pass this array as a pointer or if this method is fine. I don’t need pointers to long longs but pointers to the array.

Answer 1

It is being passed in as a pointer (language pedantry notwithstanding); nothing’s getting copied. type[] is, for the most part, the same thing as type*.

To confirm this, check out sizeof(array) in the method. You’ll see it’s the same size as sizeof(void*).

If you really want a pointer to the array, i.e. a pointer to a pointer to the long longs, you’ll need to use something like type**; but the only reason to want to do this is if you want to modify the underlying array pointer from the method, which is hardly ever the case.