c++ 한지 한 달밖에 안 되서 잘 모르겠음..


class Point_21_18

{

public:

void Print_21_18();


Point_21_18(); // 생성자

Point_21_18(int iniX, int iniY);

Point_21_18(const Point_21_18& pt_21_18);


void SetX(int value)

{ mx = value; } // 접근자

void SetY(int value)

{ my = value; }

int GetX() 

{ return mx; };

int GetY() 

{ return my; };

private:

int mx, my;

};


Point_21_18::Point_21_18()

{

mx = 0;

my = 0;

}


void Point_21_18::Print_21_18()

{

cout << "( " << mx << " & " << my <<  ")"  << endl;

}


Point_21_18::Point_21_18(const Point_21_18 &pt_21_18)

{

mx = pt_21_18.mx;

my = pt_21_18.my;

}


Point_21_18::Point_21_18(int iniX, int iniY)

{

mx = iniX;

my = iniY;

}


cout << "pt_21_18.SetX(123) = " << pt_21_18.GetX() << endl;

cout << "pt_21_18.SetY(456) = " << pt_21_18.GetY() << endl;






정상적인 실행은 되는데 


Point_21_18(const Point_21_18& pt_21_18);


Point_21_18::Point_21_18(const Point_21_18 &pt_21_18)

{

mx = pt_21_18.mx;

my = pt_21_18.my;

}


이 부분에서  

const Point_21_18 &pt_21_18

해석이 잘 안 됨.. 왜 굳이 const 랑 레퍼런스를 사용하는거야?