Question

I don’t know if I should create a destructor to delete the members of Controller that are set to the parameters passed by main which are created dynamically, because the constructor never used the new keyword to set them.

int main()  
{
    int numCars = 3;
    int numPlanes = 3;
    Machine *car= new Car[numCars];
    Machine *plane = new Plane[numPlanes];

    Controller *control = new Controller(car, plane);

    delete control;
    return 0;
}

class Controller
{
public:
    Controller(Machine *car, Machine *plane);
//Would I need to make a destructor 
//~Controller();
private:
    Machine *car;
    Machine *plane;
Controller :: Controller(Machine *car, Machine *plane)
{
    this->car = car;
    this->plane = plane;
    changeCarandPlane();
}
//destructor
//    Controller :: ~Controller()
//   {
//    delete[] car;
//    delete[] plane;
//    }
};

Answer 1

No you shouldn’t delete in the destructor. main seems to own the allocated arrays, so delete from main.

int main()  
{
    int numCars = 3;
    int numPlanes = 3;
    Machine *car= new Car[numCars];
    Machine *plane = new Plane[numPlanes];

    Controller *control = new Controller(car, plane);

    delete control;
    delete [] plane;
    delete [] car;
    return 0;
}

If you were to delete in the Controller destructor, you would have to ensure that no two instances of Controller point to the same dynamically allocated Machine arrays.

You should consider using std::vector<Machine> instead of dynamically allocated arrays, or at least some scope guards to guarantee deletion.

#include <vector>
int main()  
{
    const int numCars = 3;
    const int numPlanes = 3;
    std::vector<Machine> cars(numCars); // holds 3 default constructed Machines
    std::vector<Machine> planes(numPlanes); // holds 3 default constructed Machines

    Controller control(cars, planes);
}