作业3.23

#include<iostream>using namespace std;class cylinder{private:double radius;double high;public:cylinder(double r,double h){radius=r;high=h;}double vol(){return 3.14*radius*radius*high;}void show_vol(){cout<<"该圆柱的体积为:"<<vol()<<endl;}};int main(){cylinder v1(4,5);v1.vol();v1.show_vol();return 0;}