8-5.h

c++事例,填充表格信息,插入删除修改保存

#define PI 3.14
class Shape
{
public:
	float virtual GetArea()=0;
	float virtual GetPerim()=0;
};

class Rectangle:public Shape
{
private:
	float l,w;
public:
	Rectangle(float l=0,float w=0);
	float GetArea();
	float GetPerim();
};
Rectangle::Rectangle(float l, float w)
{
	this->l=l;
	this->w=w;
}
float Rectangle::GetArea()
{
	return l*w;
}
float Rectangle::GetPerim()
{
	return 2*(l+w);
}
class Circle:public Shape
{
private:
	float r;
public:
	Circle(float r=0);
	float GetArea();
	float GetPerim();
};
Circle::Circle(float r)
{
	this->r=r;
}
float Circle::GetArea()
{
	return r*r*PI;
}
float Circle::GetPerim()
{
	return 2*PI*r;
}