time.cpp

C++程序设计源代码例

#include <iostream.h>
class Time
{
  protected:
	int Hour;
	int Min,Sec;
  public:
	virtual void SetTime(int,int,int);
    Time(){}
	Time(const Time & t)
	{
		Hour=t.Hour,Min=t.Min ,Sec=t.Sec ;
	}
	virtual void ShowTime();
};

void Time::SetTime(int h,int m,int s)
{ 
	Hour=h,Min=m,Sec=s;
} 
void Time::ShowTime()
{
	cout<<Hour<<":"<<Min<<":"<<Sec<<endl;
} 

class NewTime :public Time
{
  public:
	NewTime(const Time & t):Time(t)
	{}
	void ShowHour();
	void ShowHour(int );
	void ShowTime();
 
};

void NewTime::ShowHour()
{
	cout<<"hour="; cout<<Hour<<endl;
}
void NewTime::ShowHour(int flag)
{
	cout<<"hour=";
	if(flag==0)
		if(Hour>12)
			cout<<Hour-12<<" PM\n";
		else
			cout<<Hour<<" AM\n";
	else

			cout<<Hour<<"\n";
}
void NewTime::ShowTime()
{
  if(Hour>12)
	cout<<Hour-12<<":"<<Min<<":"<<Sec<<" PM\n";
  else
	cout<<Hour<<":"<<Min<<":"<<Sec<<" AM\n";
}
 
void main()
{
 Time time;
 time.SetTime(23,34,45);
 cout<<"\nnow is: ";
 time.ShowTime(); 
 NewTime nt(time);
 cout<<"\nnew time's hour is:\n";
 cout<<"hour(12): ";
 nt.ShowHour(0);
 cout<<"hour(24): ";
 nt.ShowHour(); 
 Time *basetime;
 basetime=&time;
 cout<<"\ntime(24): ";
 basetime->ShowTime();
 basetime=&nt;
 cout<<"new time(12): ";
 basetime->ShowTime(); 
}