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

 1 #if ! defined(CPP10_H)
 2 #define CPP10_H
 3 #include<iostream>
 4 #include<cmath>
 5 using namespace std;
 6 class Point
 7 {
 8     double X, Y;
 9 public:
10     Point(double = 0, double = 0);
11     Point(Point&);
12     void Display()
13     {
14         cout << X << "," << Y << endl;
15     }
16     double Distance(Point&);
17     double Getx()
18     {
19         return X;
20     }
21     double Gety()
22     {
23         return Y;
24     }
25 };
26 struct Cow
27 {
28     int Color;
29     int Width;
30 };
31 struct Line
32 {
33     Point a, b;
34     Cow cw;
35 public:
36     Line(Point&, Point&, Cow&);
37     void Display();
38     Line(Line&);
39     double Distance();
40     double Area();
41 };
42 #endif

源文件cpp10.cpp

 1 #include"cpp10.h"
 2 Point::Point(double a, double b) :X(a), Y(b)
 3 {
 4 
 5 }
 6 Point::Point(Point&a)
 7 {
 8     X = a.X;
 9     Y = a.Y;
10 }
11 double Point::Distance(Point&a)
12 {
13     return sqrt((X - a.X)*(X - a.X) + (Y - a.Y)*(Y - a.Y));
14 }
15 Line::Line(Point&a1, Point&a2, Cow&a3) :a(a1), b(a2), cw(a3)
16 {
17 
18 }
19 Line::Line(Line&s) : a(s.a), b(s.b), cw(s.cw)
20 {
21 
22 }
23 void Line::Display()
24 {
25     a.Display();
26     b.Display();
27     cout << "Color=" << cw.Color << ',' << "Width=" << cw.Width << endl;
28 }
29 double Line::Distance()
30 {
31     double x = a.Getx() - b.Getx();
32     double y = a.Gety() - b.Gety();
33     return sqrt(x*x + y*y);
34 }
35 double Line::Area()
36 {
37     return cw.Width * Distance();
38 }

源文件Find10.cpp

 1 #include"cpp10.h"
 2 void main()
 3 {
 4     Point a;
 5     Point b(7.8, 9.8), c(34.5, 67.8);
 6     a = c;
 7 
 8     a.Display();
 9     b.Display();
10     cout << "两点之距：" << a.Distance(b) << endl;
11 
12     Cow cw = { 3.5 };
13     Line s(a, b, cw);
14     Line s1(s);
15 
16     cout << "线段属性如下：" << endl;
17     s1.Display();
18     cout << "线段长度：" << s1.Distance() << endl;
19     cout << "线段面积：" << s1.Area() << endl;
20 
21     system("pause");
22 }

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

 1 #if ! defined(CPP101_H)
 2 #define CPP10_H
 3 #include<iostream>
 4 #include<math.h>
 5 using namespace std;
 6 class Point
 7 {
 8 protected:
 9     double X, Y;
10 public:
11     Point(double = 0, double = 0);
12     Point(Point&);
13     virtual void Display()
14     {
15         cout << "X=" << X << ",Y=" << Y << endl;
16     }
17     double Distance(Point&);
18     virtual double Area()
19     {
20         return 0;
21     }
22     double Getx()
23     {
24         return X;
25     }
26     double Gety()
27     {
28         return Y;
29     }
30 };
31 struct Cow
32 {
33     int Color;
34     int Width;
35 };
36 class Line :public Point
37 {
38     double X2, Y2;
39     Cow cw;
40 public:
41     Line(double, double, double, double, Cow&);
42     Line(Line&);
43     void Display();
44     double Distance();
45     double Area();
46     double Getx2()
47     {
48         return X2;
49     }
50     double Gety2()
51     {
52         return Y2;
53     }
54     double Getc()
55     {
56         return cw.Color;
57     }
58     double Getw()
59     {
60         return cw.Width;
61     }
62     friend void Disp(Line&t)
63     {
64         cout << t;
65     }
66     friend ostream &operator<<(ostream&, Line);
67 };
68 #endif

源文件cpp101.cpp

 1 #include"cpp101.h"
 2 Point::Point(double a, double b) :X(a), Y(b)
 3 {
 4 
 5 }
 6 Point::Point(Point&a)
 7 {
 8     X = a.X;
 9     Y = a.Y;
10 }
11 double Point::Distance(Point&a)
12 {
13     return sqrt((X - a.X)*(X - a.X) + (Y - a.Y)*(Y - a.Y));
14 }
15 Line::Line(double a1, double a2, double a3, double a4, Cow&c) : Point(a1, a2), X2(a3), Y2(a4), cw(c)
16 {
17 
18 }
19 Line::Line(Line&s) : Point(s), X2(s.X2), Y2(s.Y2), cw(s.cw)
20 {
21 
22 }
23 double Line::Distance()
24 {
25     double x = X2 - X;
26     double y = Y2 - Y;
27     return sqrt(x*x + y*y);
28 }
29 void Line::Display()
30 {
31     cout << "X=" << X << ",Y=" << Y << ",XW=" << X2 << ",Y2=" << Y2
32         << ",Color=" << cw.Color << ",Width=" << cw.Width << endl;
33 }
34 double Line::Area()
35 {
36     return cw.Width * Distance();
37 }
38 ostream &operator<<(ostream& stream, Line obj)
39 {
40     stream << "使重载<<输出线段属性如下：" << endl;
41     stream << obj.Getx() << "," << obj.Gety() << ","
42         << obj.Getx2() << "," << obj.Gety2() << ","
43         << obj.Getc() << "," << obj.Getw() << endl;
44     return stream;
45 }

源文件Find101.cpp

 1 #include"cpp101.h"
 2 void main()
 3 {
 4     Point a;
 5     Point b(7.8, 9.8), c(34.5, 67.8);
 6     a = c;
 7 
 8     a.Display();
 9     b.Display();
10     cout << "两点之距：" << a.Distance(b) << endl;
11 
12     Cow cw = { 3,5 };
13     Line s(7.8, 9.8, 34.5, 67.8, cw);
14     Disp(s);
15     Line s1(s);
16 
17     cout << "使用Display函数输出线段属性如下：" << endl;
18     s1.Display();
19     cout << "线段长度：" << s1.Distance() << endl;
20     cout << "线段面积：" << s1.Area() << endl;
21 
22     cout << "派生类的对象赋给基类对象" << endl;
23     a.Display();
24     a = s;//派生类的对象可以赋给基类
25     cout << "面积：" << a.Area() << endl;;
26     
27     cout << "派生类的对象赋给基类对象" << endl;
28     Point *p = &s1;
29     p->Display();
30     cout << "面积：" << p->Area() << endl;
31     
32     cout << "基类对象引用派生类对象" << endl;
33     Point &d = s1;
34     d.Display();
35     cout << "面积：" << d.Area() << endl;
36     
37     system("pause");
38 }