array of pointers as function parameter

Question

I have a basic question on array and pointer in C/C++.

Say I have:

Foo* fooPtrArray[4];

How to pass the fooPtrArray into a function? I have tried:

int getResult(Foo** fooPtrArray){}  //  failed
int getResult(Foo* fooPtrArray[]){} // failed

How can I deal with pointer array?

EDIT: I once thought the error msg is from passing the wrong pointer array, but from all the responses, I realize that it's something else... (pointer assignment)

Error msg:
Description Resource Path Location Type incompatible types in assignment of 
`Foo**' to `Foo*[4]' tryPointers.cpp tryPointers line 21 C/C++ Problem

I don't quite get why it says: Foo* * to Foo*[4]. If as function parameter they are inter-change with each other, why during assignment, it give me compilation error?

I tried to duplicate the error msg with minimum code as follows:

#include <iostream>

using namespace std;

struct Foo
{
int id;
};

void getResult(Foo** fooPtrArray)
{
cout << "I am in getResult" << endl;
Foo* fooPtrArray1[4];
fooPtrArray1 = fooPtrArray;
}

int main()
{
Foo* fooPtrArray[4];
getResult(fooPtrArray);
}

Answer 1

Both

int getResult(Foo** fooPtrArray)

and

int getResult(Foo* fooPtrArray[])

as well as

int getResult(Foo* fooPtrArray[4])

will work perfectly fine (they are all equivalent).

It is not clear from your question what was the problem. What "failed"?

When passing arrays like that it normally makes sense to pass the element count as well, since the trick with allowing the array type to declay to pointer type is normally used specifically to allow passing arrays of different sizes

int getResult(Foo* fooPtrArray[], unsigned n);
...
Foo* array3[3];
Foo* array5[5];
getResult(array3, 3);
getResult(array5, 5);

But if you always going to pass arrays of strictly 4 elements, it might be a better idea to use a differently-typed pointer as a parameter

int getResult(Foo* (*fooPtrArray)[4])

In the latter case the function call will loook as follows

Foo* array[4];
getResult(&array);

(note the & operator applied to the array object).

And, finally, since this question is tagged as C++, in the latter case a reference can also be used instead of a pointer

int getResult(Foo* (&fooPtrArray)[4]);
...
Foo* array[4];
getResult(array);