1 #include <iostream>
2 using namespace std;
3 class Clock
4 {
5 public:
6 Clock(int hour = 0,int minute = 0,int second = 0);
7 void showTime()const;
8 Clock& operator++();
9 Clock operator++(int);
10 private:
11 int hour,minute,second;
12 };
13 Clock::Clock(int hour,int minute ,int second )
14 {
15 if(0<=hour&&hour<24&&0<=minute&&minute<60&&0<=second&&second<60)
16 {
17 this->hour = hour;
18 this->minute = minute;
19 this->second = second;
20 }
21 else
22 cout<<"Time error!"<<endl;
23 }
24 void Clock::showTime() const
25 {
26 cout<<hour<<":"<<minute<<":"<<second<<endl;
27 }
28 Clock&Clock::operator++()
29 {
30 second++;
31 if(second>=60)
32 {
33 second-=60;
34 minute++;
35 if(minute>=60)
36 {
37 minute-=60;
38 hour = (hour+1)%24;
39 }
40 }
41 return *this;
42 }
43 Clock Clock::operator++(int)
44 {
45 Clock old = *this;
46 ++(*this);
47 return old;
48 }
49 int main()
50 {
51 Clock myclock(23,59,59);
52 cout<<"First time output:";
53 myclock.showTime();
54 cout<<"show ++myclock:";
55 (++myclock).showTime();
56 cout<<"show myclock++:";
57 (myclock++).showTime();
58 return 0;
59 }
