C++ exercise: time class
#include <iostream>
#include <time.h>
using namespace std;
class Date {
private: //私有成员，只能在类内函数调用，外部不能直接调用
int year, month, day,hour;
void setsystemdate();
public: //公有成员，主函数通过公有成员来对其私有成员进行修改
void init(int,int,int,int);
void print_ymd();
void print_mdy();
int get_year(){
return year;};
int get_month(){
return month;};
int get_day(){
return day;}
int get_hour(){
return hour;};
bool Isleapyear();
};
void Date::setsystemdate(){
//不符合条件时的构造函数
tm *gm;
time_t t=time(NULL); //秒数，time_t为长整型
gm=localtime(&t);
//gmtime为格林尼治时间，localtime为当地时间
year=1900+gm->tm_hour;
month=gm->tm_mon+1;
day=gm->tm_mday;
hour=gm->tm_hour;
}
void Date::init(int yy,int mm,int dd,int hh){
//构造函数
if(yy>=1900&&yy<=9999) year=yy;
else{
setsystemdate();
return;
}
if(mm>=1&&mm<=12) month==mm;
else{
setsystemdate();
return;
}
if(dd>=1&&dd<=31) day=dd;
else{
setsystemdate();
return;
}
if(hh>=1&&hh<=24) hour=hh;
else{
setsystemdate();
return;
}
}
void Date::print_ymd(){
cout<<year<<"-"<<month<<"-"<<day<<"-"<<hour<<endl;
}
void Date::print_mdy(){
cout<<month<<"-"<<day<<"-"<<year<<endl;
}
bool Date::Isleapyear(){
if(year%400==0||(year%100!=0&&year%4==0)) return true;
else return false;
}
int main(){
Date date1;
date1.init(2008,13,8,20);
date1.print_ymd();
if(date1.Isleapyear()) cout<<date1.get_year()<<"leapyear"<<endl;
else cout<<date1.get_year()<<"notleapyear"<<endl;
return 0;
}
time.h file function
Function name: time
Function prototype: time_t time(time_t *timer)
Function: Get the current calendar time of the
system Function return: The current calendar time of the system, if the current calendar time cannot be obtained, return -1
Parameter description: Get when timer=NULL The calendar time of the machine. When the timer is a valid pointer, update the timer to the current time of the system, and time_t is a long type.
File: <time.h>
#include<time.h>
#include<stdio.h>
#include<dos.h>
int main()
{
time_t t;
t = time(NULL);//默认1970-1-1
printf("The number of seconds since January1, 1970 is %ld", t);
return 0;
}
Function name: localtime
Function prototype: struct tm *localtime(const time_t *timer)
Function function: Return a machine time information expressed in tm structure
Function return: Time expressed in tm structure, structure tm is defined as follows:
#ifndef _TM_DEFINED
struct tm {
int tm_sec; /* 秒 – 取值区间为[0,59] */
int tm_min; /* 分 - 取值区间为[0,59] */
int tm_hour; /* 时 - 取值区间为[0,23] */
int tm_mday; /* 一个月中的日期 - 取值区间为[1,31] */
int tm_mon; /* 月份（从一月开始，0代表一月） - 取值区间为[0,11] */
int tm_year; /* 年份，其值等于实际年份减去1900 */
int tm_wday; /* 星期 – 取值区间为[0,6]，其中0代表星期天，1代表星期一，以此类推 */
int tm_yday; /* 从每年的1月1日开始的天数 – 取值区间为[0,365]，其中0代表1月1日，1代表1月2日，以此类推 */
int tm_isdst; /* 夏令时标识符，实行夏令时的时候，tm_isdst为正。不实行夏令时的进候，tm_isdst为0；不了解情况时，tm_isdst()为负。*/
};
#define _TM_DEFINED
#endif
Parameter description: timer-the machine time obtained by using the time() function
File: <time.h>
#include<time.h>
#include<stdio.h>
#include<dos.h>
int main()
{
time_t timer;
struct tm *tblock;
timer = time(NULL);
tblock = localtime(&timer);
printf("Local time is: %s", asctime(tblock));
return 0;
}
Function name: gmtime
function prototype: struct tm *gmtime(time_t *time)
function function: get the time information represented by the structure tm
function return: the time information pointer represented by the structure tm
Parameter description: time-obtained by the function time() Time information
File: <time.h>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<dos.h>
char*tzstr="TZ=PST8PDT";
int main()
{
time_t t;
struct tm *gmt,*area;
putenv(tzstr);
tzset();
t = time(NULL);
area = localtime(&t);
printf("Local time is: %s", asctime(area));
gmt = gmtime(&t);
printf("GMT is: %s", asctime(gmt));
return 0;
}
Function name: asctime
Function prototype: char* asctime(struct tm * ptr)
Function function: Get machine time (date and time converted to ASCII code)
Function return: The format of the returned time string is: week, month, day, hour: minute ：Second, year
Parameter description: The structure pointer ptr should be obtained through the functions localtime() and gmtime()
#include<stdio.h>
#include<time.h>
int main()
{
time_t t;
time(&t);
tm *gm;
gm=localtime(&t);
printf("Today's date and time: %s", asctime(gm));
return 0;
}
Function name: ctime
Function prototype: char *ctime(const time_t *time)
Function: Get calendar time
Function return: Return string format: week, month, day, hour: minute: second, year.
Parameter description: time-this parameter Should be obtained by the function time
Owning file: <time.h>
#include<stdio.h>
#include<time.h>
int main()
{
time_t t;
time(&t);
printf("Today's date and time: %s", ctime(&t));
return 0;
}
Function name: difftime
Function prototype: double difftime(time_t time2, time_t time1)
Function: Get the time difference between two machines, in seconds.
Function return: Time difference, in seconds.
Parameter description: time1-machine time one, time2-machine time two
.This parameter should be obtained using the time function. File: <time.h>
#include<time.h>
#include<stdio.h>
#include<windows.h>
int main()
{
time_t start, end;
system("cls");//清屏
time(&start);
Sleep(5000);//等待5秒，Sleep()函数包含在windows.h的头文件里，以毫秒为单位
time(&end);
printf("The difference is: %f seconds", difftime(end, start));
return 0;
}
Function name: tzset
Function prototype: void tzset(void)
Function function: UNIX compatible function, used to get the time zone, no use in DOS environment
Function return:
Parameter description:
Owned file: <time.h>
#include<time.h>
#include<stdlib.h>
#include<stdio.h>
int main()
{
time_t td;
putenv("TZ=PST8PDT");
tzset();
time(&td);
printf("Current time = %s", asctime(localtime(&td)));
return 0;
}