e6.cpp

一、教学目的： 能理解C++中运算符重载的需要性

#include<iostream.h>          

class Increase
{
public:
	Increase(int x):value(x){}
	friend Increase&operator++(Increase&);//前增量
	friend Increase operator++(Increase&,int);//后增量
	void display()
	{
		cout<<"the value is "<<value<<endl;
	}
private:
	int value;
};
Increase& operator++(Increase&a)
{
	a.value++;
	return a;
}
Increase operator++(Increase&a,int)
{
	Increase temp(a);
	a.value++;
	return temp;
}
void main()
{
	Increase n(20);
	n.display();
	(n++).display();
	n.display();
	++n;
	n.display();
	++(++n);
	n.display();
	(n++)++;
	n.display();
}