单目运算符“++”重载为成员函数形式

来源：互联网发布：编程到底难在哪里编辑：程序博客网时间：2024/05/22 09:49

#include<iostream>
using namespace std;

class Clock
{
public:
    Clock(int NewH=0,int NewM=0,int NewS=0);
    void ShowTime();
    Clock& operator ++(); //前置单目运算符重载

    Clock operator ++(int); //后置单目运算符重载
private:
    int Hour,Minute,Second;
};
Clock::Clock(int NewH,int NewM,int NewS)
{
   if(0<=NewH&&NewH<24 && 0<=NewM&&NewM<60 && 0<NewS&&NewS<60)
   {
Hour=NewH;
Minute=NewM;
Second=NewS;
   }
   else
    cout<<"Time error!"<<endl;
}
void Clock::ShowTime()
{
cout<<Hour<<":"<<Minute<<":"<<Second<<endl;
}
Clock& Clock::operator++() //前置单目运算符重载函数
{
   Second++;
   if(Second>=60)
   {
    Second=Second-60;
    Minute++;
    if(Minute>=60)
    {
   Minute=Minute-60;
   Hour++;
   Hour=Hour%24;
    }
   }
   return *this;
}
Clock Clock::operator++(int) //后置单目运算符重载函数
{
Clock old=*this;
++(*this);
return old;
}

int main()
{
Clock myClock(23,59,59);
cout<<"First time output:";
myClock.ShowTime();
cout<<"Show myClock++:";
(myClock++).ShowTime();
cout<<"Show ++myClock:";
(++myClock).ShowTime();
}