日期类的实现-编程知识

Date.h

Test.cpp

测试代码Test.cpp

日期类的实现

代码分享

Date.h

#pragma once
#include<iostream>
using namespace std;
#include<assert.h>class Date
{//友元函数声明friend ostream& operator<<(ostream& out, Date& d);friend istream& operator>>(istream& in, Date& d);public:// 全缺省的构造函数Date(int year = 1, int month = 1, int day = 1);// 拷贝构造函数Date (const Date& d);// 赋值运算符重载// d2 = d3; -> d2.operator=(&d2, d3);Date& operator=(const Date& d);// 析构函数~Date();// 直接定义类里面，他默认是inline// 频繁调用//得到月的天数int GetMonthDay(int year, int month){assert(month>0&& month<13);static int MonthDay[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31};if (month == 2 && ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0))//千万不能少括号{return 29;}return MonthDay[month];}bool CheckDate();bool operator == (const Date& d)const;bool operator != (const Date& d)const;bool operator <(const Date& d)const;bool operator > (const Date& d)const;bool operator <=(const Date& d)const;bool operator >= (const Date& d)const;Date& operator += (int day);Date operator + (int day)const;Date& operator ++ ();// 为了区分，构成重载，给后置++，强行增加了一个int形参// 这里不需要写形参名，因为接收值是多少不重要，也不需要用// 这个参数仅仅是为了跟前置++构成重载区分Date operator ++ (int);Date& operator -= (int day);Date operator - (int day)const;//日期减日期int operator -(const Date& d)const;Date& operator -- ();Date operator -- (int);// 流插入// 不建议，因为Date* this占据了一个参数位置，使用d<<cout不符合习惯//void operator<<(ostream& out);void Printf()const{cout << _year << "年" << _month << "月" << _day << "日" << endl;}private:int _year = 1;int _month = 1;int _day = 1;
};

Test.cpp

#include"Date.h"bool Date::CheckDate()
{if (_month < 1 || _month>12|| _day<1 || _day>GetMonthDay(_year, _month)){return false;}else{return true;}
}// 全缺省的构造函数
Date::Date(int year , int month , int day )
{_year = year;_month = month;_day = day;if (!CheckDate()){cout << "日期非法" << endl;}
}
//Date d2(d1);
//Date d2 = d1;
// 拷贝构造函数
Date::Date(const Date& d)
{_year = d._year;_month = d._month;_day = d._day;}// 赋值运算符重载
// d2 = d3; -> d2.operator=(&d2, d3);
Date& Date::operator=(const Date& d)
{_year = d._year;_month = d._month;_day = d._day;return *this;
}// 析构函数
Date::~Date()
{_year = 1;_month = 1;_day = 1;
}bool Date::operator == (const Date& d)const
{return _year == d._year&& _month == d._month&& _day == d._day;
}
bool Date::operator != (const Date& d)const
{return !(*this == d);
}bool Date::operator <(const Date& d)const
{if(this->_year<d._year){return true;}else{if (this->_year == d._year && this->_month < d._month){return true;}if (this->_year == d._year && this->_month == d._month && this->_day < d._day){return true;}}return false;
}
bool Date::operator > (const Date& d)const
{return (!(*this < d)) && *this != d;//易错,或者!(*this<=d),但是要在<=函数后面
}bool Date::operator <=(const Date& d)const
{return *this < d || *this == d;
}
bool Date::operator >= (const Date& d)const
{return *this > d || *this == d;
}Date& Date::operator += (int day)
{if (day<0){return *this -= -day;}_day += day;while (_day > GetMonthDay(_year,_month)){_day -= GetMonthDay(_year, _month);++_month;if (_month == 13){++_year;_month = 1;}}return *this;
}
Date Date::operator + (int day)const
{Date tmp=*this;tmp += day;return tmp;
}Date& Date::operator ++ ()
{*this += 1;return *this;}
Date Date::operator ++ (int)
{Date tmp = *this;*this += 1;return tmp;
}Date& Date::operator -= (int day)
{if(day<0){return *this += -day;}_day -= day;while (_day < 1){--_month;if (_month == 0){--_year;_month = 12;}_day+= GetMonthDay(_year, _month);}return *this;
}
Date Date::operator - (int day)const
{Date tmp = *this;tmp -= day;return tmp;
}//日期减日期
int Date::operator -(const Date& d)const
{int flag = 1;int count = 0;//假设this大，d小Date max = (*this);Date min = d;if (max < min){max = d;min = (*this);flag = -1;}while (max>min){++min;//一般用前置++count;}return count * flag;
}Date& Date::operator -- ()
{*this -= 1;return *this;
}
Date Date::operator -- (int)
{Date tmp = *this;*this -= 1;return tmp;
}ostream& operator<<(ostream& out,Date& d)
{out << d._year << "年" <<d._month << "月" << d._day << "日" << endl;return out;
}istream& operator>>(istream& in, Date& d)
{cout << "请输入年，月，日" << endl;in >> d._year >> d._month >> d._day;if (!d.CheckDate()){cout << "日期非法" << endl;}return in;
}

测试代码Test.cpp

#include"Date.h"
using namespace std;void Test1()
{Date d1(2022,6,21);Date d2 = d1;Date d3(2022,6,1);if (d3 < d1){cout << "d3<d1" << endl;}
}void Test2()
{Date d1(2024, 4, 21);Date d2 = d1;d2 += 3000;d2.Printf();Date d3 = d1 + 300;d3.Printf();Date d4= d3++;d4.Printf();++d3;d3.Printf();}void Test3()
{Date d1(2024,4,21);Date d2 = d1 - 5000;d1 -= 20;d1.Printf();d2.Printf();
}void Test4()
{Date d1(2024,4,21);Date d2(2002,2,14);int day = d2 - d1;cout << day << "Ìì" << endl;
}void Test5()
{Date d1(2024,4,21);Date d2=d1--;d2.Printf();d1.Printf();--d1;d1.Printf();
}void Test6()
{Date d1(2024, 4, 14);Date d2 = d1 + 30000;// operator<<(cout, d1)cout << d1;cout << d2;cin >> d1 ;d2 = d1 + 30000;cout << d1 << d2;
}
int main()
{/*Test6();*/Date d1(2024, 4, 21);Date d2(2024, 4, 21);if (d1 == d2){cout << "d1 == d2" << endl;}return 0;
}