C++语言基础 例程 虚析构函数

贺老师的教学链接  本课讲解

问题的由来

#include <iostream>
using namespace std;
class Point
{
public:
    Point( ) { }
    ~Point()
    {
        cout<<"executing Point destructor"<<endl;
    }
};


class Circle:public Point
{
public:
    Circle( ) { }
    ~Circle( )
    {
        cout<<"executing Circle destructor"<<endl;
    }
private:
    int radius;
};


int main( )
{
    Point *p=new Circle;
    delete p;
    return 0;
}

使用虚析构函数

#include <iostream>
using namespace std;
class Point
{
public:
    Point( ) { }
    virtual ~Point()
    {
        cout<<"executing Point destructor"<<endl;
    }
};


class Circle:public Point
{
public:
    Circle( ) { }
    ~Circle( )
    {
        cout<<"executing Circle destructor"<<endl;
    }
private:
    int radius;
};


int main( )
{
    Point *p=new Circle;
    delete p;
    return 0;
}