pr12004.cpp

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////////////////////////////////////////
// File Name: pr12004.cpp
////////////////////////////////////////
#include <iostream>

////////////////////////////////////////
// The Date class.
////////////////////////////////////////
class Date
{
    int mo, da, yr;
    static int dys[];

public:
    Date(int m=0, int d=0, int y=0)
        { mo = m; da = d; yr = y; }
    void display() const
        { std::cout << mo << '/' << da << '/' << yr; }

    // Overloaded + operator.
    Date operator+(int) const;

    // Overloaded += operator.
    Date operator+=(int n)
        { *this = *this + n; return *this; }
};

int Date::dys[]={31,28,31,30,31,30,31,31,30,31,30,31};

// Overloaded + operator definition.
Date Date::operator+(int n) const
{
    Date dt = *this;
    n += dt.da;
    while (n > dys[dt.mo-1])
    {
        n -= dys[dt.mo-1];
        if (++dt.mo == 13)
        {
            dt.mo = 1;
            dt.yr++;
        }
    }
    dt.da = n;

    return dt;
}

////////////////////////////////////////
// The main() function.
////////////////////////////////////////
int main()
{
    Date olddate(2,20,1997);
    olddate += 21;            // three weeks hence
    olddate.display();

    return 0;
}