c++实验3-1

一、问题及代码

#include<iostream.h>class Time{public:Time(int=0,int=0,int=0);void show_time( ); //根据is_24和from0，输出适合形式-20:23:5/8:23:5 pm/08:23:05 pmvoid add_seconds(int a); //增加n秒钟void add_minutes(int b); //增加n分钟void add_hours(int c); //增加n小时static void change24();  //改变静态成员is_24，在12和24时制之间转换static void changefrom0();   //改变静态成员from0，切换是否前导0private:static bool is_24; //为true时，24小时制，如20:23:5；为flase，12小时制，显示为8:23:5 pmstatic bool from0; //为true时，前导0，8:23:5显示为08:23:05int hour;int minute;int sec;};//下面写出静态成员的初始化及各成员函数的定义……int main( ){Time t1(23,14,25),t2(8,45,6);cout << "24时制, 不前导0：" << endl;cout << "    t1是：";t1.show_time();cout << "    t2是：";t2.show_time();t1.add_hours(10);t2.add_hours(10);Time::changefrom0();cout << "10小时后, 切换是否前导0：" << endl;cout << "    t1是：";t1.show_time();cout << "    t2是：";t2.show_time();Time::change24();cout << "换一种制式" << endl;cout << "    t1是：";t1.show_time();cout << "    t2是：";t2.show_time();return 0;}Time::Time(int h, int m, int s){hour = h, minute = m, sec = s;}bool Time::is_24 = true;bool Time::from0 = true;void Time::show_time(){if (is_24){if (from0){cout << (hour<10? "0":"") << hour <<":"<< (minute < 10 ? "0":"") << minute << ':' << (sec < 10 ? "0":"") << sec << endl;}else{cout << hour << ':' << minute << ':' << sec << endl;}}else{if (from0){cout << (hour < 10||(hour - 12 >=0 && hour - 12 < 10) ? "0":"") << (hour > 12 ? hour-12 : hour) << ':' << (minute < 10 ? "0":"") << minute << ':' << (sec < 10 ? "0":"") << sec << ' '  << (hour > 11 ? "pm" : "am") << endl;}else{cout <<(hour>12?hour-12:hour)<<':'<<minute<<':'<<sec<<' '<<(hour>11?"pm":"am") <<endl;}}}void Time::add_seconds(int a){int k,l;k=a/60;l=a%60;sec=sec+l;minute=minute+k;if(sec>=60)minute=minute+1;if(minute>=60)hour=hour+1;if(hour>=24)hour=0;}void Time::add_minutes(int b){int d,q;d=b/60;q=b%60;minute=minute+q;hour=hour+d;if(minute>=60)hour=hour+1;if(hour>=24)hour=hour-24;}void Time::add_hours(int c){int v;v=c%24;hour=hour+v;if(hour>=24)hour=hour-24;}void Time::change24(){is_24=!is_24;if(is_24)cout<<"已换成24制"<<endl;elsecout<<"已换成12制"<<endl;}void Time::changefrom0(){from0 = !from0;if (from0) cout << "已切换为前导0输出。" << endl;else cout << "已切换为非前导0输出。" << endl;}

二、运行结果：三、心得体会：　　第二个C++程序，有很多错误，这些都只能通过实践来慢慢改正，所以应该多多练习。　　C++，我会好好学的！、知识点总结：类函数和成员函数，调用要分清。选择判断要更熟悉。对博文提交的程序书写规范很重要，最起码的要求：（1）缩格排版；（2）一句一行；（3）花括号位置；（4）适度的注释。