运算符重载

#include<iostream> using namespace std; class Clock{ int hour,minute,second; public: Clock(int hour=0,int minute=0,int second=0) ; void showtime()const; Clock& operator++(); Clock operator++(int); }; Clock::Clock(int hour,int minute,int second) 切记带默认形参的构造函数，声明时带参数，但定义时不需要带参数，，， { if(0<=hour&&hour<24&&0<=minute&&minute<60&&0<=second&&second<60) { this->hour=hour; this->minute=minute; this->second=second; } else cout<<"Time error!"<<endl; } Clock &Clock::operator++()返回值为当前对象的引用。 { second++; if(second>=60) { second-=60; minute++; if(minute>=60) {minute-=60; hour++; hour%=24; } } return *this; } Clock Clock::operator++(int)返回值不是当前对象的引用。 { Clock old=*this; ++(*this); return old; } void Clock::showtime() const { cout<<this->hour<<":"<<this->minute<<":"<<this->second<<endl; } int main() { Clock c1(23,59,59); c1.showtime(); (c1++).showtime(); (++c1).showtime(); //system("pause"); }