#include
using namespace std;
//定义圆类
int main() {
___________________; //声明圆类对象r,默认构造(圆的半径=1)
cout<<"Radius:"<<r.getRadius();
cout<<",Area:"<<___________________;
cout<<",Perimeter:"<<r.getPerimeter()<<endl;
cout<<endl;
___________________; //改变圆的半径为6
cout<<"Radius:"<<___________________;
cout<<",Area:"<<r.getArea();
cout<<",Perimeter:"<<r.getPerimeter()<<endl;
cout<<endl;
___________________; //声明另一个圆类对象r1(半径初值为8)
cout<<"Radius:"<<r1.getRadius();
cout<<",Area:"<<r1.getArea();
cout<<",Perimeter:"<<___________________<<endl;
cout<<endl;
return 0;
}
输入
无
输出
圆的半径、面积和周长
输入样例 1
无
输出样例 1
Radius:1,Area:3.14159,Perimeter:6.28319
Radius:6,Area:113.097,Perimeter:37.6991
Radius:8,Area:201.062,Perimeter:50.2655
#include <iostream>
using namespace std;
//定义圆类
class Circle
{
public:
float r;
public:
Circle() : r(1) {}
Circle(float _r) : r(_r) {}
void setRadius(float r) { this->r = r; }
float getRadius() { return r; }
float getArea() { return 3.14 * r * r; }
float getPerimeter() { return 3.14 * r * 2; }
};
int main() {
Circle r; //声明圆类对象r,默认构造(圆的半径=1)
cout<<"Radius:"<<r.getRadius();
cout<<",Area:"<<r.getArea();
cout<<",Perimeter:"<<r.getPerimeter()<<endl;
cout<<endl;
r.setRadius(6); //改变圆的半径为6
cout<<"Radius:"<<r.getRadius();
cout<<",Area:"<<r.getArea();
cout<<",Perimeter:"<<r.getPerimeter()<<endl;
cout<<endl;
Circle r1(8); //声明另一个圆类对象r1(半径初值为8)
cout<<"Radius:"<<r1.getRadius();
cout<<",Area:"<<r1.getArea();
cout<<",Perimeter:"<<r.getPerimeter()<<endl;
cout<<endl;
return 0;
}