C实验报告-实验4继承与派生.doc

实验4 继承与派生一、实验目的和要求（1）掌握派生类的定义方法和派生类构造函数的定义方法。（2）掌握不同继承方式的情况下，基类成员在派生类中的访问权限。（3）掌握在多继承方式的情况下，构造函数与析构函数的调用时机与顺序。二、实验内容和原理（1）实验指导书P86 12任选一题。（2）实验指导书P89 34任选一题。三、实验环境联想计算机，Windows XP操作系统，Visual C+ 6.0四、算法描述及实验步骤（1）输入源程序。（2）检查程序有无错误(包括语法错误和逻辑错误)，有则改之。（3）编译和连接，仔细分析编译信息，如有错误应找出原因并改正之。（4）运行程序，分析结果，在原有程序得出正确结果后，修改程序，将其改写为在类模板外定义，再按第（3）步骤运行。（5）将调试好的程序保存在自己的用户目录中，文件名自定。五、调试过程（1）2（2）4六、实验结果（1）2(2)4七、总结（1）掌握构造函数和析构函数的定义方法（2）构造函数调用顺序：先调用所有基类的构造函数，然后调用派生类的构造函数；（3）析构函数调用顺序：先调用派生类的析构函数，然后调用基类的析构函数，其顺序正好与构造函数调用顺序相反。八、附录：（1）代码如下#includeusing namespace std;class Base1public:Base1()coutconstructing Base1endl;Base1()coutdestructing Base1endl;class Base2public:Base2()coutconstructing Base2endl;Base2()coutdestructing Base2endl;class Derived1:public Base1,virtual public Base2public:Derived1()coutconstructing Derived1endl;Derived1()coutdestructing Derived1endl;class Derived2:public Base1,virtual public Base2public:Derived2()coutconstructing Derived2endl;Derived2()coutdestructing Derived2endl;class Derived3:public Derived1,virtual public Derived2public:Derived3()coutconstructing Derived3endl;Derived3()coutdestructing Derived3endl;int main()Derived3 obj;return 0;（2）4代码如下#includeusing namespace std;const double PI=3.14;class Shapepublic:double area()constreturn 0.0;void display();class TwoDimShape:virtual public Shape;class ThreeDimShape:virtual public Shape;class Circle:public TwoDimShapepublic:Circle(double myr)R=myr;double area()constreturn PI*R*R;void display()coutArea of circle is ;private:double R;class Rectangle:public TwoDimShapepublic:Rectangle(double myl,double myw)L=myl;W=myw;double area()constreturn L*W;void display()coutArea of rectangle is;private:double L,W;class Cylinder:public ThreeDimShapepublic:Cylinder(double myr,double myh)R=myr;H=myh;double area()constreturn 2*PI*R*(H+R);void display()coutsuperficial area of cylinder is;private:double R,H;class Cube:public ThreeDimShapepublic:Cube(double myl,double myw,double myh)L=myl;W=myw;H=myh;double area()const return 2*(L*W+L*H+W*H);void display()coutSuperficial area of rectangularparallelepied is ;private:double L,W,H;int main()Circle c(3.0); double area(); area=c.area(); c.display(); coutareaendl; Rectangle rec(4.0,5.0); area=rec.area(); rec.display(); coutareaendl; Cylinder cy(3.0,4.0);