源程序：
#include <iostream>
#include <string>
using namespace std;
class Date
{
public:
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 Print() const
{
cout << year << "/" << month << "/" << day << "; ";
}
protected:
int year, month, day;
};
class DateTime :public Date
{
public:
DateTime(int y, int m, int d, int h, int mi, int s) :Date(y, m, d)
{
SetTime(h, mi, s);
}
void SetTime(int h, int mi, int s)
{
hours = h;
minutes = mi;
seconds = s;
}
void Print() const
{
cout << hours << ':' << minutes << ':' << seconds << '
';
}
private:
int hours, minutes, seconds;
};
int main()
{
DateTime dt(2018,7,16,12,30,0);
DateTime *pdt = &dt;
((Date)dt).Print();
dt.Print();
((Date *)pdt)->Print();
pdt->Print();
system("pause");
return 1;
}
运行结果：
