C++中的虚析构函数的作用

虚析构函数的作用：

1. 当直接delete子类的指针对象时，delete会先调用子类的析构函数，再调用父类的析构函数。

   #include
   using namespace std;
   
   class AA
   {
   public:
   	AA(int a = 0)
   	{
   		this->a = a;		
   	}
   	~AA()
   	{
   		cout << "AA类的虚析构函数" << endl;
   	}
   	virtual void print()
   	{
   		cout << "AA的print()函数" << endl;
   	}
   
   protected:
   	int a;
   private:
   };
   
   class BB:public AA
   {
   public:
   	BB(int a = 0, int b = 0)
   	{
   		this->a = a;
   		this->b = b;
   	}
   	~BB()
   	{
   		cout << "BB类的虚析构函数" << endl;
   	}
   	virtual void print()
   	{
   		cout << "BB类的print()函数" << a << "	" << b << endl;
   	}
   
   protected:
   private:
   	int b;
   };
   
   void howToDelete(AA *pBase)
   {
   	delete pBase;
   }
   
   void main()
   {
   	BB *b1 = new BB(1, 2);
   
   	b1->print();
   
   	delete b1;
   
   	cout << endl;
   
   	//howToDelete(b1);
   
   	system("pause");
   
   
   }

2. 实验现象如下