C++ //练习 15.22 对于你在上一题中选择的类，为其添加合适的虚函数及公有成员和受保护的成员。

C++ Primer（第5版） 练习 15.22

练习 15.22 对于你在上一题中选择的类，为其添加合适的虚函数及公有成员和受保护的成员。

环境：Linux Ubuntu（云服务器）

工具：vim

 

代码块

class Shape {
	public:
	Shape(){}
	virtual ~Shape(){}
	virtual double getArea() = 0;
};
class Rectangle: public Shape{
	public:
	Rectangle(){}
	Rectangle(double l, double w): length(l), width(w){}
	~Rectangle(){}
	virtual double getArea() const override { return length * width; }

	protected:
	double length = 0.0;
	double width = 0.0;
};
class Circle: public Shape{
	public:
	Circle(){}
	Circle(double r): radius(r){}
	~Circle(){}
	virtual double getArea() const override { return 3.14 * radius * radius; }

	protected:
	double radius = 0.0;
};
class Sphere: public Shape{
	public:
	Sphere(){}
	Sphere(double r): radius(r){}
	~Sphere(){}
	virtual double getArea() const override { return 4 * 3.14 * radius * radius; }

	protected:
	double radius = 0.0;
};
class Cone: public Shape{
	public:
	Cone(){}
	Cone(double r, double l): radius(r), length(l){}
	~Cone(){}
	virtual double getArea() const override { return 3.14 * radius * radius + 3.14 * radius * length; }

	protected:
	double radius = 0.0;
	double length = 0.0;
};