本文给出一个关于继承性的综合例子,该例子编写一个有关日期(年、月、日)和时间(时、分、秒)的程序。该程序建立三个类,其中一个是日期的类Date,一个是时间的类Time,另一个是日期和时间类DateTime,它是前面两个类为基类的派生类。
下面是该程序的源码:
#include #include #include typedef char string80[80];
class Date { public: Date() {} Date(int y, int m, int d) { SetDate(y, m, d); } void SetDate(int y, int m, int d) { Year = y; Month = m; Day = d; } void GetStringDate(string80 &Date) { sprintf(Date, "%d/%d/%d", Year, Month, Day); } protected: int Year, Month, Day; };
class Time { public: Time() {} Time(int h, int m, int s) { SetTime(h, m, s); } void SetTime(int h, int m, int s) { Hours = h; Minutes = m; Seconds = s; } void GetStringTime(string80 &Time) { sprintf(Time, "%d:%d:%d", Hours, Minutes, Seconds); } protected: int Hours, Minutes, Seconds; };
class TimeDate:public Date, public Time { public: TimeDate():Date() {} TimeDate(int y, int mo, int d, int h, int mi, int s):Date(y, mo, d), Time(h, mi, s) {} void GetStringDT(string80 &DTstr) { sprintf(DTstr, "%d/%d/%d;%d:%d:%d", Year, Month, Day, Hours, Minutes, Seconds); } };
void main() { TimeDate date1, date2(1998, 8, 12, 12, 45, 10); string80 DemoStr; date1.SetDate(1998, 8, 7); date1.SetTime(10, 30, 45); date1.GetStringDT(DemoStr); cout<<"The date1 date and time is:"< date1.GetStringDate(DemoStr); cout<<"The date1 date is:"< date1.GetStringTime(DemoStr); cout<<"The date1 time is:"< date2.GetStringDT(DemoStr); cout<<"The date2 date and time is:"< }
| 该程序中,对象的数据成员的值是通过成员函数获取数据成员的字符串,然后再使用输出语句进行输出的。 |