d_8_1.cpp

C++应用教程原码,里面包含该书中有十三章内容的代码,详细具体

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
class Triangle;
class Rectangle {
	friend float operator +(const Rectangle r,const Triangle t);
	friend string operator >(const Rectangle r,const Triangle t);
private:
	float a,b,area;
public:

	Rectangle()
	{ cout << "请输入矩形的长和宽:";
	  cin >> a >>b;
	  area = a * b;
	}
};

class Triangle {
private:
	float a, h, area;
public:
	friend float operator +(const Rectangle r,const Triangle t);
	friend string operator >(const Rectangle r,const Triangle t);
	Triangle()
	{ cout << "请输入三角形的底和高";
	  cin >> a >> h;
	  area = 0.5 * a * h;
	}
};

float operator +(const Rectangle r,const Triangle t)
{   cout << "矩形的面积是" << r.area << "，三角形的面积是" << t.area << endl; 
	return (r.area + t.area);
}

string operator >(const Rectangle r,const Triangle t)
{ if (r.area > t.area)
    return "大于";
  else
    return "小于";
}

void main()
{ Rectangle r;
  Triangle t;
  cout << "矩形的面积" << ( r > t) << "三角形的面积" << endl;
  cout << "矩形和三角形的面积之和为:"<< (r+t);
  cin.get(); cin.get(); //等待结束，以便调测程序，可以删除
}