C++语言基础 例程 初见对象

贺老师的教学链接  本课讲解

问题：求圆柱体积

//面向过程

#include <iostream>
using namespace std;
int main()
{
     double r, h, v;
     cin>>r>>h;
     v = 3.14 * r * r * h;
     cout<<v<<endl;
     return 0;
}

#include <iostream>
using namespace std;
class Cup{
private:
    double radius;
    double height;
public:
    Cup(double r, double h){
        radius = r;
        height = h;
    }
    double getvolume(){
        return 3.14 * radius * radius * height;
    }
};
int main(){
    double r, h;
    cin>>r>>h;
    Cup c(r, h);
    cout<<c.getvolume()<<endl;
    return 0;
}