今天小编给大家分享一下C++怎么实现比较日期大小的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。
一、目的
用来比较两个日期。日期格式：2023-03-31 09:16:56。
二、代码
//std::wstring strA = L"2023-03-31 09:16:56";//std::wstring strB = L"2023-03-31 09:21:34";bool LessThanEx(std::wstring strA, std::wstring strB){std::wstring strLeftA, strRightA;std::wstring strLeftB, strRightB;{std::wstring strLeft, strRight;std::size_t nIndex = strA.find(L" ");if (nIndex!=std::string::npos){strLeft = strA.substr(0,nIndex);strRight = strA.substr(nIndex+1);std::wstring wsDivide = L"-";strLeft.replace(strLeft.find(wsDivide),wsDivide.length(),L"");strLeft.replace(strLeft.find(wsDivide),wsDivide.length(),L"");wsDivide = L":";strRight.replace(strRight.find(wsDivide),wsDivide.length(),L"");strRight.replace(strRight.find(wsDivide),wsDivide.length(),L"");}strLeftA = strLeft;strRightA = strRight;}{std::wstring strLeft, strRight;std::size_t nIndex = strB.find(L" ");if (nIndex!=std::string::npos){strLeft = strB.substr(0,nIndex);strRight = strB.substr(nIndex+1);std::wstring wsDivide = L"-";strLeft.replace(strLeft.find(wsDivide),wsDivide.length(),L"");strLeft.replace(strLeft.find(wsDivide),wsDivide.length(),L"");wsDivide = L":";strRight.replace(strRight.find(wsDivide),wsDivide.length(),L"");strRight.replace(strRight.find(wsDivide),wsDivide.length(),L"");}strLeftB = strLeft;strRightB = strRight;}__int64 nLeftA = std::stoi(strLeftA);__int64 nLeftB = std::stoi(strLeftB);__int64 nRightA = std::stoi(strRightA);__int64 nRightB = std::stoi(strRightB);if(nLeftA < nLeftB){return true;}else if(nLeftA > nLeftB){return false;}else{if(nRightA >= nRightB){return false;}return true;}return true;}//CString strA = _T("2023-03-31 09:16:56");//CString strB = _T("2023-03-31 09:21:34");bool LessThan(CString strA, CString strB){CString strLeftA, strRightA;CString strLeftB, strRightB;{CString strLeft, strRight;int nIndex = strA.Find(_T(" "));if (nIndex > -1){strLeft = strA.Left(nIndex);strRight = strA.Mid(nIndex+1,strA.GetLength() - nIndex-1);strLeft.Replace(_T("-"),_T(""));strRight.Replace(_T(":"),_T(""));}strLeftA = strLeft;strRightA = strRight;}{CString strLeft, strRight;int nIndex = strB.Find(_T(" "));if (nIndex > -1){strLeft = strB.Left(nIndex);strRight = strB.Mid(nIndex+1,strB.GetLength() - nIndex-1);strLeft.Replace(_T("-"),_T(""));strRight.Replace(_T(":"),_T(""));}strLeftB = strLeft;strRightB = strRight;}__int64 nLeftA = _tstoi64(strLeftA);__int64 nLeftB = _tstoi64(strLeftB);__int64 nRightA = _tstoi64(strRightA);__int64 nRightB = _tstoi64(strRightB);if(nLeftA < nLeftB){return true;}else if(nLeftA > nLeftB){return false;}else{if(nRightA >= nRightB){return false;}return true;}return true;}三、补充
除了比较大小，C++还可以实现计算日期相差多少天，下面是实现代码，希望对大家有所帮助
#include <iostream>#include <stdio.h>#include <algorithm>using namespace std;bool isLeap(int year) {return (year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0);}int main() {//定义好平年和闰年每月的天数int monthDays[13][2] = {{0,0},{31,31},{28,29},{30,30},{31,31},{30,30},{31,31},{30,30},{31,31},{30,30},{31,31},{30,30},{31,31}};int time1, year1, month2, days1;int time2, year2, month3, days2;int numbers =1;// 输入两个日期cout << "输入两个日期，空格分隔";cin >> time1 >> time2;if (time1>time2){int temp = time1;time1 = time2;time2 = temp;}//拆解日期，分为年，月，号year1 = time1 / 10000; month2 = time1 / 100 % 100; days1 = time1 % 100;year2 = time2 / 10000; month3 = time2 / 100 % 100; days2 = time2 % 100;//第一个日期 累加到 第二个日期while (year1 < year2 || month2 < month3 || days1 < days2) {days1++;// 在第一个日期基础上 加一天//加一天后，相应的月，年可能也要做一定的变化if (days1 == monthDays[month2][isLeap(year1)]+1) {//当前号超过当前月最高天数：月份加1，号变成下月的1号month2++;days1 = 1;}if (month2 == 13) {//月份超过12个月 ：年份加1,月份变成下年的1月year1++;month2 = 1;}numbers++;}cout << numbers << endl;return 0;}以上就是“C++怎么实现比较日期大小”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网行业资讯频道。
