Name of the Program:

Write a C++ program to create a class called DATE. Accept two valid dates of the form dd/mm/yy. Implement the following operations by overloading the operators + and -. After each operation ,display the result by overloading the << operator.
1. no_of_days=d1-d2, where d1 and d2 are date objects, d1>=d2 and no_of_days is an integer
2. d2=d1+no_of_days, where d1 is a DATE object and no_of_dys is an integer.

Theory:

In operator overloading, we can give special meanings to operators, when they are used with user-defined classes. For example, to overload the + operator for your class, you would provide a member-function named operator+ on your class. The following set of operators is commonly overloaded for user-defined classes:

• = (assignment operator)
• .+ - * (binary arithmetic operators)
• += -= *= (compound assignment operators)
• == != (comparison operators)

Algorithm:

Code:

date.cpp

#include<iostream>
using namespace std;
class date
{
     int dd,mm,yy;
     int a[13];
     long double dateno;
     void getno();
     public:
     date()
     {
             a[1]=a[3]=a[5]=a[7]=a[8]=a[10]=a[12]=31;
             a[4]=a[6]=a[9]=a[11]=30;
             a[2]=28;
             dd=mm=yy=1;
     }
     void getdate();
     friend ostream& operator<<(ostream&,date&);
     long double operator-(date&);
     date operator+(long double);
};
void date::getdate()
{
     cout<<"\n Enter date";
     cout<<"\n\t day(dd):";
     cin>>dd;
     cout<<"\n\t\ month(mm):";
     cin>>mm;
     cout<<"\n\t year(yy):";
     cin>>yy;
     while((yy%4!=0&&dd>a[mm])||(yy%4==0 && mm==2 && dd>29) ||dd<=0 || mm>12 || mm<=0 )
     {
             cout<<"\n Invlid entry";
             getdate();
     } 
     getno();
}
void date::getno()
{
     int m=1;
     dateno=(long double)yy*365+yy/4;
     if(yy%4>0)
     dateno++;
     while(m!=mm)
     {
             dateno+=a[m];
             if(yy%4==0 && m==2)
             dateno++;
             m++;
     }
     dateno+=dd;
}
ostream& operator<<(ostream &out,date &d1)
 {
      out<<d1.dd<<"/"<<d1.mm<<"/"<<d1.yy;
      return out;
 } 
 long double date::operator-(date &b)
 {
     return(dateno-b.dateno);
 }

date date::operator+(long double b)
{
     for(int i=1;i<=b;i++)
     {
             dd++;
             if(dd>a[mm])
             {
                     mm++;
                     dd=1;
             }
             if(mm>12)
             {
                     yy++;
                     mm=1;
             }
             if(yy%4==0)
                     a[2]=29;
     }
     return *this;
}
int main()
{
     date d1,d2,d3;
     d1.getdate();
     cout<<"\n\td1="<<d1;
     d2.getdate();
     cout<<"\n\td2="<<d2;
     long double diff, days;
     diff=d1-d2;
     cout<<"\n\n The difference between the two dates = ";
     cout<<diff<<endl;
     cout<<"\n\n Enter the no. of days to be added to the date "<<d1<<" :";
     cin>>days;
     d3=d1+days;
     cout<<"\n New date is..."<<d3<<endl;
     return 0;
}

Steps for obtaining output:

Steps for checking output-

• Locate the folder in which the file is present in the terminal.
• Execute the command "g++ the "
• Execute ethe command "./a.out"

Output:

Enter date day(dd):29

 month(mm):02

 year(yy):2012

 d1=29/2/2012

Enter date day(dd):31

 month(mm):01

 year(yy):2012

 d2=31/1/2012

The difference between the two dates = 29

Enter the no. of days to be added to the date 29/2/2012 :29

New date is...29/3/2012

Screenshots: