C++继承——矩形和长方体

Rectangle矩形类

/*矩形类*/
class Rectangle
{
private:double L = 0;double W = 0;
public:Rectangle() = default;Rectangle(double a, double b);double GetArea();	/*矩形面积*/double GetGirth();	/*矩形周长*/
};
/*构造函数*/
Rectangle::Rectangle(double a, double b) : L{ a }, W{ b } {}
/*矩形面积*/
double Rectangle::GetArea()
{double S = L * W;return S;
}
/*矩形周长*/
double Rectangle::GetGirth()
{double L = 2 * (this->L + W);return L;
}

Cuboid长方体类

/*长方体类*/
class Cuboid : public Rectangle 
{
private:double H = 0;
public:Cuboid() = default;Cuboid(double a, double b, double c);double GetVolume();        /*长方体体积*/double GetSurfaceArea();   /*长方体表面积*/
};
/*构造函数*/
Cuboid::Cuboid(double a, double b, double c) : Rectangle{ a,b }, H{ c } {}
/*长方体体积*/
double Cuboid::GetVolume()
{double V = H * GetArea();return V;
}
/*长方体表面积*/
double Cuboid::GetSurfaceArea()
{double S = 2 * GetArea() + H * GetGirth();return S;
}

测试：

#include "Rectangle.h"#include <iostream>
using namespace std;int main(void)
{Rectangle Re{ 4,4 };cout << "矩形面积：" << Re.GetArea() << endl;cout << "矩形周长：" << Re.GetGirth() << endl;Cuboid Cu{ 3,3,3 };cout << "底面积：" << Cu.GetArea() << endl;cout << "体积：" << Cu.GetVolume() << endl;cout << "底周长：" << Cu.GetGirth() << endl;cout << "表面积：" << Cu.GetSurfaceArea() << endl;return 0;
}

测试结果：