In what cases do I use malloc and/or new?

Question

I see in C++ there are multiple ways to allocate and free data and I understand that when you call malloc you should call free and when you use the

Answer 1

In the following scenario, we can't use new since it calls constructor.

class  B  {
private:
    B *ptr;
    int x;
public:
    B(int n)  {
        cout<<"B: ctr"<x = n + 10;
    }
    ~B()  {
        //delete ptr;
        free(ptr);
        cout<<"B: dtr"<