C++ 删除继承的 class

Question

Let's say there is a class Object and then another class Cat that inherits Object . Next, there is a list of Object * (pointers). Then, I create a new Cat and put it into the list. After some time I want to delete all Cats and call delete on each member of the list. Does it call destructor of Cat ?

Answer 1

Yes if you marked the destructor of object as virtual.

class Object {
  public:
  virtual ~Object(){} //make the base class destructor virtual
};

class cat : public Object {
  public:
  virtual ~cat(){} // now this gets called when a pointer to Object that is a cat is destroyed
}

Answer 2

If the destructor of Object is virtual, yes.

Answer 3

What you describe is precisely the situation where virtual destructors come in. Read the C++ FAQ .

Answer 4

Yes, if class Object (the base class) destructor is declared virtual, otherwise you run into undefined behavior which you don't want.