《日期类》的模拟实现

目录

前言：

头文件类与函数的定义Date.h

实现函数的Date.cpp

测试Test.cpp

运行结果：

前言：

我们在前面的两章初步学习认识了《类与对象》的概念，接下来我们将实现一个日期类，是我们的知识储备更加牢固。

头文件类与函数的定义Date.h

#pragma once
#define _CRT_SECURE_NO_WARNIGS 1
#include<iostream>
using namespace std;

class Date
{
public:
	friend ostream& operator<<(ostream& out, const Date& d);
	int GetMonthDay(int _year, int _month)
	{
		int day[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
		if ((_year % 4 == 0) && (_year % 100 != 0) || (_year % 400 == 0))
		{
			day[2] = 29;
		}

		return day[_month];
	}

	Date(int year = 2000, int month = 1, int day = 1)
	{
		if (month > 12 || day > GetMonthDay(year, month))
		{
			cout << "Setting error!!!" << endl;
			exit(-1);
		}
		_year = year;
		_month = month;
		_day = day;
	}
	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);
	Date& operator+=(int day);
	Date operator+(int day);
	Date& operator++();
	Date operator++(int);
	Date& operator-=(int day);
	Date operator-(int day);
	Date& operator--();
	Date operator--(int);
	int operator-(const Date& d);
private:
	int _year;
	int _month;
	int _day;
};

实现函数的Date.cpp

#include"Data.h"
bool Date::operator==(const Date& d)
{
	return (_year == d._year) && (_month == d._month) && (_day == d._day);
}
bool Date::operator!=(const Date& d)
{
	return !(*this == d);
}
bool Date::operator>(const Date& d)
{
	if (_year > d._year)
	{
		return true;
	}
	else if (_year < d._year)
	{
		return false;
	}
	if (_month > d._month)
	{
		return true;
	}
	else if (_month < d._month)
	{
		return false;
	}
	if (_day > d._day)
	{
		return true;
	}
	return false;
}
bool Date::operator>=(const Date& d)
{
	return (*this > d) || (*this == d);
}

bool Date::operator<(const Date& d)
{
	return !(*this >= d);
}
bool Date::operator<=(const Date& d)
{
	return !(*this > d);
}

Date& Date::operator+=(int day)
{
	_day += day;
	while (_day > GetMonthDay(_year, _month))
	{
		_day -= GetMonthDay(_year, _month);
		_month++;
		if (_month == 13)
		{
			_month = 1;
			_year++;
		}
	}
	return *this;
}

Date Date::operator+(int day)
{
	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)
{
	_day -= day;
	while (_day <= 0)
	{
		_month--;
		if (_month == 0)
		{
			_month = 12;
			_year--;
		}
		_day += GetMonthDay(_year, _month);
	}
	return *this;
}

Date Date::operator-(int day)
{
	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;
}

int Date::operator-(const Date& d)
{
	int flag = 1;
	Date max = *this;
	Date min = d;
	if (max < min)
	{
		max = d;
		min = *this;
		flag = -1;
	}
	int count = 0;
	while (max != min)
	{
		++min;
		++count;
	}
	return flag * count;
}

ostream& operator<<(ostream& out, const Date& d)
{
	out << d._year << "年" << d._month << "月" << d._day << "号";
	return out;
}

测试Test.cpp

#include"Data.h"
int main()
{
	Date d1(2024, 3, 10);
	cout << d1 << endl;
	Date d2(2024, 6, 17);
	cout << d2 << endl;
	printf("相差天数：");
	cout << (d2 - d1) << endl;
	return 0;
}

运行结果：