C++模拟打印日历

    类和函数的声明部分：

#include<iostream>using namespace std;class Date{friend  void print_date(int year,int month);//打印日历friend ostream& operator<<(ostream& _cout, const Date& d);friend istream& operator>>(istream& _cin, Date& d);public:Date(int year,int month,int day);//构造函数Date(const Date& d);//拷贝构造函数Date& operator=(const Date& d);Date operator+(int day);Date& operator++();Date operator++(int);Date operator-(int day);int operator-(/*const*/ Date& d);Date& operator--();Date operator--(int);bool operator>(const Date& d);bool operator<(const Date& d);bool operator==(const Date& d);bool operator!=(const Date& d);bool operator>=(const Date& d);bool operator<=(const Date& d);int days_everymonth(int year,int month);//所求月的天数Date& display(const Date& d);//打印某天日期private:int _year;int _month;int _day;};bool judge_leap(int year);//判断是否闰年void print_date(int year,int month);//打印日期int week_firstday(int year,int day);//计算要求月数的第一天是星期几

函数实现：

ostream& operator<<(ostream& _cout, const Date& d) { _cout<<d._year<<"--"<<d._month<<"--"<<d._day; return _cout; } istream& operator>>(istream& _cin, Date& d) { _cin>>d._year>>d._month>>d._day; return _cin; } Date::Date(int year = 2016,int month = 1,int day = 1) :_year(year) ,_month(month) ,_day(day){if(day > days_everymonth(_year,_month)){_day = day - days_everymonth(_year,_month);_month +=1;if(_month>12){_month -= 12;_year +=1;}}} Date::Date(const Date& d) { _year = d._year; _month = d._month; _day = d._day; } Date& Date::operator=(const Date& d) { if(this != &d) { _year = d._year; _month = d._month; _day = d._day; } return *this; } Date Date::operator+(int day) { _day = _day + day;  if(_day > days_everymonth(_year,_month)) { _day = _day - days_everymonth(_year,_month); _month +=1; if(_month>12) { _month = 1; _year +=1; } }return *this; } Date& Date::operator++() { _day++;  if(_day > days_everymonth(_year,_month)) { _day = _day - days_everymonth(_year,_month); _month +=1; if(_month>12) { _month = 1; _year +=1; } } return *this; } Date Date::operator++(int) { ++_day; if(_day > days_everymonth(_year,_month)) { _day = _day - days_everymonth(_year,_month); _month +=1; if(_month>12) { _month = 1; _year +=1; } } return *this; } Date Date::operator-(int day) { _day = _day - day; if(_day <= 0) { _month -=1; _day +=  days_everymonth(_year,_month);  if(_month == 0) { _month = 12; _year -=1; } } return *this; } int Date::operator-(Date& d) { Date max; Date min; if(*this > d) { max = *this;         min = d; } else {     max = d; min = *this; } int day = 0; while(max > min) { min = min +1; day++; } return day; } Date& Date::operator--() { _day--; if(_day == 0) { _month -= 1; if(_month == 0) { _month = 12; _year -= 1; } _day = days_everymonth(_year,_month); } return *this; } Date Date::operator--(int) { --_day; if(_day == 0) { _month -= 1; if(_month == 0) { _month = 12; _year -= 1; } _day = days_everymonth(_year,_month); } return *this; } bool Date::operator>(const Date& d) { if(_year > d._year) return true; else if(_year < d._year) return false; else { if(_month > d._month) return true; else if(_month < d._month) return false; else {     if(_day > d._day) return true; else return false; } } } bool Date::operator<(const Date& d) { if(_year < d._year) return true; else if(_year > d._year) return false; else { if(_month < d._month) return true; else if(_month > d._month) return false; else { if(_day < d._day) return true; else return false; } } } bool Date::operator==(const Date& d) { if(_year != d._year) return false; else { if(_month != d._month) return false; else { if(_day == d._day) return true; else return false; } } } bool Date::operator!=(const Date& d) { if((_year != d._year) || (_month != d._month) || (_day != d._day)) return true; else  return false; } bool Date::operator>=(const Date& d) { if(_year >= d._year) return true; else { if(_month >= d._month) return true; else { if(_day >= d._day) return true; else return false; } } } bool Date::operator<=(const Date& d) { if(_year <= d._year) return true; else { if(_month <= d._month) return true; else { if(_day <= d._day) return true; else return false; } } }  static bool judge_leap(int year) { if((year%400 == 0) || ((year%4 == 0) && (year%100 != 0))) return true; else return false; } static int week_firstday(int year,int month) { Date d1(1949,9,21);//新中国自1949年开始使用公元纪年法 int week = 3;//公元1949年9月21日为周一 int day = 0; Date d2(year,month,1); day = d2 - d1;//统计目标月份的第一天离起始日期相差多少天 week += day%7; if(week > 7) { week -= 7; } return week; } Date& Date::display(const Date &d) { cout<<d._year<<"--"<<d._month<<"--"<<d._day<<endl; return *this; } int Date::days_everymonth(int year,int month) { int day[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; if(judge_leap(year) == true) day[2] = 29;//闰年的2月有29天 return day[month]; } void print_date(int year,int month)//打印日历 { cout<<year<<"年"<<month<<"月"<<endl; cout<<"日"<<" "<<"一"<<" "<<"二"<<" "<<"三"<<" "<<"四"<<" "<<"五"<<" "<<"六"<<endl; int i = 0; int j = 0; Date temp(year,month,1); int week = week_firstday(year,month); int day = temp.days_everymonth(year,month);//需要打印月的天数 int k = 1; for(i=0; i<week; i++) { cout<<"   "; } for(i=0; i<6; i++) { for(j=0; j<7; j++) { if(i == 0) { if(j == 7-week) break; } if(k <= day) printf("%2d ",k++); } cout<<endl; } }

测试部分：

 

<pre name="code" class="cpp">void Funtest() { Date d1(2016,10,12); cin>>d1; d1++; cout<<d1<<endl; Date d2; d2 = d1; d2.operator-(33); d2.display(d2); int ret = d1.operator<(d2); print_date(2016,3); } int main() { Funtest(); system("color 1E"); system("pause"); return 0; }

注意测试时打印某个月的日历不要超过1949年9月，因为它是我们的日期原点，我们的代码是以它为基准点朝后写的。

还有不知你注意到这句话没有system("color 1E"); 它是用来改变我们输出时的字体和背景颜色的，来学习一下吧！

其中color后面的0是背景色代号，A是前景色代号。各颜色代码如下： 

0=黑色 1=蓝色 2=绿色 3=湖蓝色 4=红色 5=紫色 6=黄色 7=白色 8=灰色 9=淡蓝色

 A=淡绿色 B=淡浅绿色 C=淡红色 D=淡紫色 E=淡黄色 F=亮白色
           读者可根据自己的喜好设置背景颜色