#include “A.h”
#include
using namespace std;
int main (){
// This compilation unit needs to use the x and y global variables declared in A.cpp.
// In order not to have undeclared symbols (semantic error) for x and y, it needs to
// include an “extern” declaration for these to variables, which is provided by
// A.h (#included above).
cout << "x : " << x << endl;
cout << "y : " << y << endl; // y undeclared in this scope
}