prog3.cpp

来自「C++语言程序设计题典」· C++ 代码 · 共 30 行

#include <iostream.h>
class Sample
{
	int n;
public:
	Sample() {}
	Sample(int i) { n=i; }
	friend Sample operator - (Sample &,Sample &);
	friend Sample operator + (Sample &,Sample &);
	void disp() { cout << "n=" << n << endl; }
};
Sample operator - (Sample &s1,Sample &s2)
{
	int m=s1.n-s2.n;
	return Sample(m);
}
Sample operator + (Sample &s1,Sample &s2)
{
	int m=s1.n+s2.n;
	return Sample(m);
}
void main()
{
	Sample s1(10),s2(20),s3;
	s3=s2-s1;
	s4.disp();
	s3=s1+s2;
	s4.disp();
}