pr12003.cpp

来自「c++编程宝典源码及Quincy99编译器 是《标准C++编程宝典》电子工业出」· C++ 代码 · 共 70 行

////////////////////////////////////////
// File Name: pr12003.cpp
////////////////////////////////////////
#include <iostream>

////////////////////////////////////////
// The Date class.
////////////////////////////////////////
class Date
{
    int mo, da, yr;

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 operators.
    int operator==(Date& dt) const;
    int operator<(Date&) const;
};

// Overloaded equality operator definition.
int Date::operator==(Date& dt) const
{
    return (this->mo == dt.mo &&
            this->da == dt.da &&
            this->yr == dt.yr);
}

// Overloaded less-than operator definition.
int Date::operator<(Date& dt) const
{
    if (this->yr == dt.yr)    {
        if (this->mo == dt.mo)
            return this->da < dt.da;
        return this->mo < dt.mo;
    }
    return this->yr < dt.yr;
}

////////////////////////////////////////
// The main() function.
////////////////////////////////////////
int main()
{
    Date date1(12,7,1941),
         date2(2,22,1990),
         date3(12,7,1941);

    if (date1 < date2)
    {
        date1.display();
        std::cout << " is less than ";
        date2.display();
    }

    std::cout << '\n';

    if (date1 == date3)
    {
        date1.display();
        std::cout << " is equal to ";
        date3.display();
    }

    return 0;
}