一个简单的c++程序

#include<iostream>
using namespace std;
class Time
{
public://这里一定要使用public，不能使用private，否则对象无法调用这些数据
int hour;
int minute;
int sec;
};
void set_time(Time &t, int hour=0, int minute=0, int sec=0);
void show_time(Time &t);
int main()
{
Time t1;
set_time(t1, 12, 23, 34);
show_time(t1);
Time t2;
set_time(t2);
show_time(t2);
system("pause");
return 0;
}
void set_time(Time &t, int hour, int minute, int sec)//t2的实参采用默认值
{
t.hour = hour;
t.minute = minute;
t.sec = sec;
}
void show_time(Time &t)
{
cout<<"请输出时间:"<<endl;
cout<<t.hour<<":"<<t.minute<<":"<<t.sec<<endl;
}