04737_C++程序设计_第10章_面向对象设计实例

10.6.2

使用包含的参考程序及运行结果。

头文件cpp10.h

源文件cpp10.cpp

源文件Find10.cpp

头文件cpp10.h

 #if ! defined(CPP10_H)
 #define CPP10_H
 #include<iostream>
 #include<cmath>
 using namespace std;
 class Point
 {
     double X, Y;
 public:
     Point(double = , double = );
     Point(Point&);
     void Display()
     {
         cout << X << "," << Y << endl;
     }
     double Distance(Point&);
     double Getx()
     {
         return X;
     }
     double Gety()
     {
         return Y;
     }
 };
 struct Cow
 {
     int Color;
     int Width;
 };
 struct Line
 {
     Point a, b;
     Cow cw;
 public:
     Line(Point&, Point&, Cow&);
     void Display();
     Line(Line&);
     double Distance();
     double Area();
 };
 #endif

源文件cpp10.cpp

 #include"cpp10.h"
 Point::Point(double a, double b) :X(a), Y(b)
 {

 }
 Point::Point(Point&a)
 {
     X = a.X;
     Y = a.Y;
 }
 double Point::Distance(Point&a)
 {
     return sqrt((X - a.X)*(X - a.X) + (Y - a.Y)*(Y - a.Y));
 }
 Line::Line(Point&a1, Point&a2, Cow&a3) :a(a1), b(a2), cw(a3)
 {

 }
 Line::Line(Line&s) : a(s.a), b(s.b), cw(s.cw)
 {

 }
 void Line::Display()
 {
     a.Display();
     b.Display();
     cout << "Color=" << cw.Color << ',' << "Width=" << cw.Width << endl;
 }
 double Line::Distance()
 {
     double x = a.Getx() - b.Getx();
     double y = a.Gety() - b.Gety();
     return sqrt(x*x + y*y);
 }
 double Line::Area()
 {
     return cw.Width * Distance();
 }

源文件Find10.cpp

 #include"cpp10.h"
 void main()
 {
     Point a;
     Point b(7.8, 9.8), c(34.5, 67.8);
     a = c;

     a.Display();
     b.Display();
     cout << "两点之距：" << a.Distance(b) << endl;

     Cow cw = { 3.5 };
     Line s(a, b, cw);
     Line s1(s);

     cout << "线段属性如下：" << endl;
     s1.Display();
     cout << "线段长度：" << s1.Distance() << endl;
     cout << "线段面积：" << s1.Area() << endl;

     system("pause");
 }

10.6.4

使用继承的参考程序和运行结果。

头文件cpp101.h

源文件cpp101.cpp

源文件Find101.cpp

头文件cpp101.h

 #if ! defined(CPP101_H)
 #define CPP10_H
 #include<iostream>
 #include<math.h>
 using namespace std;
 class Point
 {
 protected:
     double X, Y;
 public:
     Point(double = , double = );
     Point(Point&);
     virtual void Display()
     {
         cout << "X=" << X << ",Y=" << Y << endl;
     }
     double Distance(Point&);
     virtual double Area()
     {
         return ;
     }
     double Getx()
     {
         return X;
     }
     double Gety()
     {
         return Y;
     }
 };
 struct Cow
 {
     int Color;
     int Width;
 };
 class Line :public Point
 {
     double X2, Y2;
     Cow cw;
 public:
     Line(double, double, double, double, Cow&);
     Line(Line&);
     void Display();
     double Distance();
     double Area();
     double Getx2()
     {
         return X2;
     }
     double Gety2()
     {
         return Y2;
     }
     double Getc()
     {
         return cw.Color;
     }
     double Getw()
     {
         return cw.Width;
     }
     friend void Disp(Line&t)
     {
         cout << t;
     }
     friend ostream &operator<<(ostream&, Line);
 };
 #endif

源文件cpp101.cpp

 #include"cpp101.h"
 Point::Point(double a, double b) :X(a), Y(b)
 {

 }
 Point::Point(Point&a)
 {
     X = a.X;
     Y = a.Y;
 }
 double Point::Distance(Point&a)
 {
     return sqrt((X - a.X)*(X - a.X) + (Y - a.Y)*(Y - a.Y));
 }
 Line::Line(double a1, double a2, double a3, double a4, Cow&c) : Point(a1, a2), X2(a3), Y2(a4), cw(c)
 {

 }
 Line::Line(Line&s) : Point(s), X2(s.X2), Y2(s.Y2), cw(s.cw)
 {

 }
 double Line::Distance()
 {
     double x = X2 - X;
     double y = Y2 - Y;
     return sqrt(x*x + y*y);
 }
 void Line::Display()
 {
     cout << "X=" << X << ",Y=" << Y << ",XW=" << X2 << ",Y2=" << Y2
         << ",Color=" << cw.Color << ",Width=" << cw.Width << endl;
 }
 double Line::Area()
 {
     return cw.Width * Distance();
 }
 ostream &operator<<(ostream& stream, Line obj)
 {
     stream << "使重载<<输出线段属性如下：" << endl;
     stream << obj.Getx() << "," << obj.Gety() << ","
         << obj.Getx2() << "," << obj.Gety2() << ","
         << obj.Getc() << "," << obj.Getw() << endl;
     return stream;
 }

源文件Find101.cpp

 #include"cpp101.h"
 void main()
 {
     Point a;
     Point b(7.8, 9.8), c(34.5, 67.8);
     a = c;

     a.Display();
     b.Display();
     cout << "两点之距：" << a.Distance(b) << endl;

     Cow cw = { , };
     Line s(7.8, 9.8, 34.5, 67.8, cw);
     Disp(s);
     Line s1(s);

     cout << "使用Display函数输出线段属性如下：" << endl;
     s1.Display();
     cout << "线段长度：" << s1.Distance() << endl;
     cout << "线段面积：" << s1.Area() << endl;

     cout << "派生类的对象赋给基类对象" << endl;
     a.Display();
     a = s;//派生类的对象可以赋给基类
     cout << "面积：" << a.Area() << endl;;

     cout << "派生类的对象赋给基类对象" << endl;
     Point *p = &s1;
     p->Display();
     cout << "面积：" << p->Area() << endl;

     cout << "基类对象引用派生类对象" << endl;
     Point &d = s1;
     d.Display();
     cout << "面积：" << d.Area() << endl;

     system("pause");
 }