Difference between two declarations involving a pointer and an array

Question

What is the difference between int *a[3] and int (*a)[3]?

Answer 1

If you have any doubt, using this g++ trick is often handy:

#include 

template < class T > void describe(T& )
{
  // With msvc, use __FUNCSIG__ instead
  std::cout << __PRETTY_FUNCTION__ << std::endl;
}

int main(int argc, char* argv[])
{
  int *a[3];
  describe(a);

  int (*b)[3];
  describe(b);

  return EXIT_SUCCESS;
}

Compile it with g++ and run it, you'll get:

void describe(T&) [with T = int*[3]]
void describe(T&) [with T = int (*)[3]]

So, they are definitely NOT the same ! What you have is:

1. an array of 3 pointers to int.
2. a pointer to an array of 3 ints.