How to return an array from a function?

Question

How can I return an array from a method, and how must I declare it?

int[] test(void); // ?? 

Answer 1

int* test();

but it would be "more C++" to use vectors:

std::vector< int > test();

EDIT
I'll clarify some point. Since you mentioned C++, I'll go with new[] and delete[] operators, but it's the same with malloc/free.

In the first case, you'll write something like:

int* test() {     return new int[size_needed]; } 

but it's not a nice idea because your function's client doesn't really know the size of the array you are returning, although the client can safely deallocate it with a call to delete[].

int* theArray = test(); for (size_t i; i < ???; ++i) { // I don't know what is the array size!     // ... } delete[] theArray; // ok. 

A better signature would be this one:

int* test(size_t& arraySize) {     array_size = 10;     return new int[array_size]; } 

And your client code would now be:

size_t theSize = 0; int* theArray = test(theSize); for (size_t i; i < theSize; ++i) { // now I can safely iterate the array     // ... } delete[] theArray; // still ok. 

Since this is C++, std::vector<T> is a widely-used solution:

std::vector<int> test() {     std::vector<int> vector(10);     return vector; } 

Now you don't have to call delete[], since it will be handled by the object, and you can safely iterate it with:

std::vector<int> v = test(); std::vector<int>::iterator it = v.begin(); for (; it != v.end(); ++it) {    // do your things } 

which is easier and safer.