Date Library in C++

Here you will get to know about the Date library, which is built using c++ programming language.

Table of Contents

• Overview
• Methods and Operators
  • Constructors
  • Print Date
  • Get Methods
  • Assignment Operators
  • Arithmetic Operators
  • Relational Operators
  • isLeapYear Method
• Exception Handling

Overview

Date Library in C++ is a lightweight, user-friendly and comprehensive library designed for working with date in C++ applications. this library provide various date related tasks and offers extensive functionalities for data manipulation, comparision, parsing and other operations. It provides developers with a reliable and efficient solution for handling dates in their C++ projects.

Methods And Operators

Constructors

• It consists of Date class with default constructor to get the current date, a parametrized constructor to give the user defined date, and a copy constructor to copy the date of other Date class object in the new Date class object

  Date();
  Date(string str);
  Date(const Date &other);

  try
  {
  Date date1;`
  Date date2("29/3/2004");
  Date date3("9-4-2022");
  Date date4(date2);
  }catch(DateException dateException) // try-catch block is to catch the 
  dateException in case of invalid/out-of-range dates
  {
  cout<<dateException.what()<<endl;
  }

Print Date

• The cout operator is overloaded to print the date

  ostream& operator<<(ostream& oo, Date& d);

  cout<<date1<<endl;

  cout<<date2<<endl;

  cout<<date3<<endl;

  cout<<date4<<endl;

Get Methods

• The Date class consists of get methods to get day of week, month, year, month name, month short name, day of week name and day of week short name.

• To get Day of Month of a Date class object

  int getDayOfMonth();

• To get Day of Week of a Date class object

  int getDayOfWeek();

• To get Month of Year of a Date class object

  int getMonth();

• To get Year of a Date class object

  int getYear();

• To get Name of Month of a Date class object

  string getMonthString();

• To get Short Name of Month of a Date class object

  string getMonthShortString();

• To get Name of Day Of Week of a Date class object

  string getDayOfWeekString();

• To get Short Name Of Day Of Week of a Date class object

  string getDayOfWeekShortString()

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date("23/6/2023");
int day_of_month = date.getDayOfMonth(); // gives the day in month
int day_of_week = date.getDayOfWeek(); // gives the day of week with Sunday as day 1
int month = date.getMonth(); // gives the month of the year
int year = date.getYear(); // gives the year
string month_string = date.getMonthString(); // gives the name of month like January, February, March etc.
string month_short_string = date.getMonthShortString(); // gives the short name of month like Jan, Feb, Mar etc.
string day_of_week_string = date.getDayOfWeekString(); // gives the name of day of week like Sunday, Monday, Tuesday etc.
string day_of_week_short_string = date.getDayOfWeekShortString(); // gives the short name of day of week like Sun, Mon, Tue etc.
cout<<day_of_month<<endl;
cout<<day_of_week<<endl;
cout<<month<<endl;
cout<<year<<endl;
cout<<month_string<<endl;
cout<<month_short_string<<endl;
cout<<day_of_week_string<<endl;
cout<<day_of_week_short_string<<endl;
}catch(DateException dateException) // try-catch block is to catch the dateException in case of invalid/out-of-range dates
{
cout<<dateException.what()<<endl;
}
return 0;
}

Assignment Operators

• Date class consists of two assignment operators to assign the new Date class object date of another object of the same class or date in the form of string

• To assign the date in form of string to the object of Date class

  Date& operator = (const Date &other);

• To assign the date in of another object of same class

  Date& operator = (string dateString);

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date("23/6/2023");
Date date1;
date1 = date; // Assigns the date Of date object to date1 
cout<<date1<<endl;
Date date2;
date2 = "24/12/2024"; // Assigns the date2 "24/12/2024" date
cout<<date2<<endl;

}catch(DateException dateException)
{
cout<<dateException.what()<<endl;
}
return 0;
}

Arithmetic Operators

• Date class consists of arithmetic operators to add days, subtract days, post increment and decrement the date

• Addition operator

  Date operator+(int days);

• Subtraction operator

  Date operator-(int days);

• Shorthand Addition Operator

  void operator +=(int number);

• Shorthand Subtraction Operator

  void operator -=(int number);

• Post Increment Operator

  void operator++(int);

• Post Decrement Operator

  void operator--(int);

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date("24/5/2023");
Date date1;
date1 = date + 60;  // Add 60 days to Date date
cout<<date1<<endl;
Date date2;
date2 = date - 66; // Subtracts 66 days from Date date
cout<<date2<<endl;
Date date3;
date3 += 50; // Add 50 days to Date date3, which has current date;
cout<<date3<<endl;
Date date4("25/6/2022");
date4 -= 23; // Add 23 days to Date date4, which has "24/6/2022" date;
cout<<date4<<endl;
date++; // Increments the Date date by one day
cout<<date<<endl;
date--; // Decrements the Date date by one day
cout<<date<<endl;
}catch(DateException dateException)
{
cout<<dateException.what()<<endl;
}
return 0;
}

Relational Operators

• Date class consists of relational operators to perform the comparision based operations between the Date class objects

• Less than Operators

  bool operator<(const Date &other);

• Greater than Operators

  bool operator>(const Date &other);

• Less than or Equal to Operator

  bool operator<=(const Date &other);

• Greater than or Equal to Operator

  bool operator>=(const Date &other);

• Equal to Operator

  bool operator==(const Date &other);

• Not Equal to Operator

  bool operator!=(const Date &other);

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date1("4/8/2018");
Date date2("5/8/2018");
Date date3("4/8/2018");
cout<<(date1<date2)<<endl;
cout<<(date1>date2)<<endl;
cout<<(date3<=date2)<<endl;
cout<<(date1>=date3)<<endl;
cout<<(date1==date2)<<endl;
cout<<(date2!=date3)<<endl;
bool f = false;
cout<<f<<endl;
}catch(DateException dateException)
{
cout<<dateException.what()<<endl;
}
return 0;
}

isLeapYear Method

• Date class consists of isLeapYear Method to check whether the follwing date falls in leap year or not

  bool isLeapYear();

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date1("4/8/2018");
Date date2("20/8/2022");
Date date3("4/12/2024");
cout<<date1.isLeapYear()<<endl;
cout<<date2.isLeapYear()<<endl;
cout<<date3.isLeapYear()<<endl;
}catch(DateException dateException)
{
cout<<dateException.what()<<endl;
}
return 0;
}

Exception Handling

• The Date class throws DateException when an invalid or out-of-range date is encountered. It includes the invalid dates like 30/2/2022 and dates before 1/1/1901.
• To know the exception the declaration and operation performed on the Date class object should be inside try-catch block with catch block having the object of DateException class
• To know which exception has been raised '<name_of_object_defined_in_catch>.what()' method should be called inside the catch block

Example

#include<iostream>
#include<date>
using namespace std;
using namespace myDate;

int main()
{
try
{
Date date1("4/8/2018");
Date date2("29/2/2022"); // As Date is invalid this will raise exception
Date date3;
int x = -56000;
date3 -= 80000; // As subtraction gives date less than 1/1/1901 this will also raise exception
date3 += x; // As addition gives date less than 1/1/1901 this will also raise exception
}catch(DateException dateException)
{
cout<<dateException.what()<<endl;
}
return 0;
}