demo_1_single_inheritance_constructor_destrctor_2.cpp

对于一个初涉VC＋＋的人来书

//*********************************************************
// 单继承多级派生的派生类的构造函数和析构函数的调用次序
//*********************************************************

# include <iostream.h>

class Point
{
public:
	Point(int a=0,int b=0)
	{
		x=a;
		y=b;
		cout<<"Constructing Point Object: "<<'['<<x<<','<<y<<']'<<endl;	
	}
	~Point()
	{
		cout<<"Destructing Point Object: "<<'['<<x<<','<<y<<']'<<endl;
	}
protected:
	int x,y;
};

class Circle:public Point
{
public:
	Circle(int a=0,int b=0,int r=0):Point(a,b)
	{
		radius=r;
		cout<<"Constructing Circle Object: "<<'['<<radius<<']'<<'['<<x<<','<<y<<']'<<endl;
	}
	~Circle()
	{
		cout<<"Destructing Circle Object: "<<'['<<radius<<']'<<'['<<x<<','<<y<<']'<<endl;
	}
protected:
	int radius;
};

class Cylinder:public Circle
{
public:
	Cylinder(int a=0,int b=0,int r=0,int h=0):Circle(a,b,r)
	{
		height=h;
		cout<<"Constructing Cylinder Object: "<<'['<<height<<']'<<'['<<radius<<']'<<'['<<x<<','<<y<<']'<<endl;
	}
	~Cylinder()
	{
		cout<<"Destructing Cylinder Object: "<<'['<<height<<']'<<'['<<radius<<']'<<'['<<x<<','<<y<<']'<<endl;
	}
protected:
	int height;
};

int main() //主程序仅仅完成对象的构造和析构
{
	Cylinder cylinder1(10,20,30,40); //创建一个二级派生的派生类对象
//	Cylinder cylinder2;

	return 0;
}

/*
Constructing Point Object: [10,20]
Constructing Circle Object: [30][10,20]
Constructing Cylinder Object: [40][30][10,20]
Destructing Cylinder Object: [40][30][10,20]
Destructing Circle Object: [30][10,20]
Destructing Point Object: [10,20]
***************************************************
Constructing Point Object: [0,0]
Constructing Circle Object: [0][0,0]
Constructing Cylinder Object: [0][0][0,0]
Destructing Cylinder Object: [0][0][0,0]
Destructing Circle Object: [0][0,0]
Destructing Point Object: [0,0]
*/