期末之7继承派生

 以point类和Rectangle类为例，继承与派生

#include <iostream>
using namespace std;
class point
{
public:
	void initpoint(float x = 0, float y = 0)
	{
		this->x = x;
		this->y = y;
	}
	void move(float offX, float offY)
	{
		x += offX;
		y += offY;
	}
	float getX() const
	{
		return x;
	}
	float getY() const
	{
		return y;
	}
private:
	float x, y;
};
class rectangle : public point {	//派生类定义部分
public:	//新增公有函数成员
	void initrectangle(float x, float y, float w, float h) {
		initpoint(x, y); //调用基类公有成员函数
		this->w = w;
		this->h = h;
	}
	float getH() const { return h; }//常成员函数，不能改变成员变量值
	float getW() const { return w; }
private:	//新增私有数据成员
	float w, h;
};

int main() {
	rectangle rect;	//定义Rectangle类的对象
	//设置矩形的数据
	rect.initrectangle(2, 3, 20, 10);
	rect.move(3, 2);	//移动矩形位置
	cout << "The data of rect(x,y,w,h): " << endl;
	//输出矩形的特征参数
	cout << rect.getX() << ", "
		<< rect.getY() << ", "
		<< rect.getW() << ", "
		<< rect.getH() << endl;
	return 0;
}