demo_4_virtual_destrctor_function_a.cpp

对于一个初涉VC＋＋的人来书

//*********************************************************
// 虚析构函数
//*********************************************************

# include <iostream.h>

class Point
{
public:
	Point(float a,float b):x(a),y(b){}
	~Point(){cout<<"Executing Point Destructor"<<endl;}
private:
	float x;
	float y;
};

class Circle:public Point
{
public:
	Circle(float a,float b,float r):Point(a,b),radius(r){}
	~Circle(){cout<<"Dxecuting Circle Destructor"<<endl;}
private:
	float radius;
};

int main()
{
//	Point *p=new Point(2.5f,1.8f);        // Executing Point Destructor
//	Circle *p=new Circle(2.5f,1.8f,4.5f); // Executing Circle,Point Destructor 

    //赋值兼容
	Point *p=new Circle(2.5f,1.8f,4.5f);  // Executing Point Destructor 
	
	delete p; //析构问题出现: 虽然申请派生类动态空间,但仅析构基类空间
	
	return 0;
}