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 }