Coordinate.h

-----------------------------------------------------------------------------

#ifndef COORDINATE_H
#define COORDINATE_H
class Coordinate
{
?? ?//friend Coordinate &operator-(Coordinate &Coor);?? ??? ??? ?//友元一重運算符重載
public:
?? ?Coordinate(int x = 0, int y = 0);?? ??? ??? ??? ??? ??? ?

?? ?Coordinate& operator-();?? ??? ??? ??? ??? ??? ??? ??? ??? ?//成員函數一重運算符重載
?? ?/*?? ?前置/后置 ++?? ?*/
?? ?Coordinate& operator++();?? ??? ??? ??? ??? ??? ??? ??? ??? ?//前置++
?? ?Coordinate operator++(int);?? ??? ??? ??? ??? ??? ??? ??? ??? ?//后置++
?? ?int getX();
?? ?int getY();
private:
?? ?int m_iX;
?? ?int m_iY;
};

#endif

Coordinate.cpp

--------------------------------------------------------------------------

#include "Coordinate.h"

Coordinate::Coordinate(int x,int y)
{
?? ?m_iX = x;
?? ?m_iY = y;
}

Coordinate & Coordinate::operator-()
{
?? ?m_iX = -m_iX;
?? ?m_iY = -m_iY;
?? ?return *this;
}

Coordinate & Coordinate::operator++()
{
?? ?m_iX++;
?? ?m_iY++;
?? ?return *this;
}

Coordinate Coordinate::operator++(int)
{
?? ?Coordinate Old(*this);

?? ?m_iX++;
?? ?m_iY++;
?? ?return Old;
}




int Coordinate::getX()
{
?? ?return m_iX;
}

int Coordinate::getY()
{
?? ?return m_iY;
}

main.cpp

--------------------------------------------------------------------------

#include <iostream>
#include "Coordinate.h"
using namespace std;


int main()
{
?? ?Coordinate *coor = new Coordinate(1, 3);

?? ?cout<< coor->getX()<<","<<coor->getY()<<endl;
?? ?cout << ((*coor)++).getX() << ","
?? ??? ?<< ((*coor)++).getY() << endl;

?? ?delete coor;
?? ?coor = NULL;

?? ?system("pause");
?? ?return 0;
}
----------------------------------------------------------

問題? 當后置++ 輸出的結果是 2,3 。正好和1，4相反

求解惑