操作符重载实例

#include <ctime>
#include <iostream>

using namespace std;

class stopWatch{
public:
stopWatch();
void setTime(int newMin, int newSec);
stopWatch operator - (stopWatch&);
void showTime();
private:
int min;
int sec;
};

stopWatch::stopWatch(){
min = 0;
sec = 0;
}

void stopWatch::setTime(int newMin, int newSec){
min = newMin;
sec = newSec;
}

stopWatch stopWatch::operator-(stopWatch& anotherTime){
stopWatch tempTime;
int second;

second = min * 60 + sec - (anotherTime.min * 60 + anotherTime.sec);
if (second < 0){
second = -second;
}

tempTime.min = second / 60;
tempTime.sec = second % 60;
}

void stopWatch::showTime(){
if (min > 0){
cout << min << "minutes" << sec << "seconds\n";
}
else{
cout << sec << "seconds\n";
}
}

int main(){
stopWatch startTime, endTime, usedTime;
cout << "按回车键开始!";
cin.get();

time_t curtime = time(0); //获取当前系统时间
tm tim = *localtime(&curtime); //根据当前时间获取当地时间
int min, sec;
min = tim.tm_min; //得到当前时间的分
sec = tim.tm_sec;// 得到当前时间的秒
startTime.setTime(min, sec);

cout << "按回车键结束";
cin.get();

curtime = time(0); //获取当前系统时间
tim = *localtime(&curtime); //根据当前时间获取当地时间
min = tim.tm_min; //得到当前时间的分
sec = tim.tm_sec;// 得到当前时间的秒
endTime.setTime(min, sec);

usedTime = endTime - startTime;
cout << "用时";
usedTime.showTime();

return 0;
}