605.cpp

C++实训教程

//605.NumPP demo	friend  operator()
#include <iostream.h>

class Num
{
	friend Num operator+(Num ob, int i);
	friend Num operator+(int i, Num ob);
	int count;
  public:
	Num(int cc=0){count=cc;}
	Num& operator=(int i);
   void Show(){cout <<count<<endl;}
};

Num& Num::operator=(int i)
{  count=i;  return *this;}

Num operator+(Num ob, int i) // This handles ob+int.
{  Num temp;  temp.count=ob.count+i;  return temp;}

Num operator+(int i, Num ob) // This handles int+ob.
{  Num temp;  temp.count=ob.count+i;  return temp;}

main(void)
{
	Num obj;
	obj=10;
	obj.Show();	// outputs 10
	obj=10+obj;				// add object to integer
	obj.Show();	// outputs 20
	obj=obj+12;				// add integer to object
	obj.Show();	// outputs 32
	return 0;
}
/*
10
20
32
*/