实验4_构造函数与析构函数.doc

实验四构造函数与析构函数1、实验目的：1）掌握构造函数和析构函数定义方法；2）掌握构造函数的重载、具有默认值的构造函数的使用方法；3）加深对构造函数的特殊用途的理解。2）分析下面程序中的对象传递，写出输出结果。#includeclass Cylinderpublic:Cylinder()Cylinder(double r,double h);void setcylinder(double r,double h);double getradius()return radius;double getheight()return height;double volume();double surface_area();private:double radius;double height;const double PI=3.1415926;Cylinder:Cylinder(double r,double h)radius=r;height=h;void Cylinder:setcylinder(double r,double h)radius=r;height=h;double Cylinder:volume()double vol;vol=PI*radius*radius*height;return vol;double Cylinder:surface_area()double area;area=2*PI*radius*height+2*PI*radius*radius;return area;void main()Cylinder cylinder1(7.0,12.0),cylinder2;cylinder2.setcylinder(12.3,18.7);coutthe radius of cylinder1 is:tcylinder1.getradius()endl;coutthe height of cylinder1 is:tcylinder1.getheight()endl;coutthe volume of cylinder1 is:tcylinder1.volume()endl;coutthe surfacearea of cylinder1 is:tcylinder1.surface_area()endl;coutthe radius of cylinder2 is:tcylinder2.getradius()endl;coutthe height of cylinder2 is:tcylinder2.getheight()endl;coutthe volume of cylinder2 is:tcylinder2.volume()endl;coutthe surfacearea of cylinder2 is:tcylinder2.surface_area()endl;运行结果：3）根据注释将下面的程序补充完整#includeclass testprivate:int num;double f1;Public: test(); test(int a,double b);/声明重载的构造函数int get_num()return num;double get_f1()return f1;test:test(int a,double b)num=a;f1=b;/定义重载的构造函数int main()test a; couta.get_num()endl; couta.get_f1()endl;test b(2,5.5);coutb.get_num()endl; coutb.get_f1()endl;return 0;22 编写并调试程序编写一个实现两个数相减的类的测试程序，请写出类的定义，构成一个完整的程序，要求调用类的构造函数和析构函数时均有明确的输出信息。#includeclass Chaint a,b,c;public:Cha(int,int); Cha()cout析构endl;void print();Cha:Cha(int x,int y) cout构造endl; a=x; b=y;void Cha:prin