成员函数版本实现算术运算符的重载
全局函数版本实现算术运算符的重载 

#include <iostream>
using namespace std;
class Number//定义一个数字类
{//因为a和b是私有成员，全局进行访问需要要friend进行声明friend const Number operator*(const Number &L,const Number &R);friend const Number operator/(const Number &L,const Number &R);
private:int a;int b;
public://无参构造Number(){}//有参构造并列表初始化Number(int a,int b):a(a),b(b){}//成员函数实现+运算符重载const Number operator+(const Number &R)const{Number sum;sum.a=a+R.a;sum.b=b+R.b;return sum;}//成员函数实现-运算符重载const Number operator-(const Number &R)const{Number sub;sub.a=a-R.a;sub.b=b-R.b;return sub;}void show()//将结果显示出来{cout<<"a="<<a<<"   "<<"b="<<b<<endl;}
};
//全局函数实现*运算符重载
const Number operator*(const Number &L,const Number &R)
{Number mul;mul.a=L.a*R.a;mul.b=L.b*R.b;return mul;
}
//全局函数实现/运算符重载
const Number operator/(const Number &L,const Number &R)
{Number divid;divid.a=L.a/R.a;divid.b=L.b/R.b;return divid;
}
int main()
{Number p1(55,7);Number p2(8,6);Number p3=p1+p2;cout<<"p1的a,b"<<"   ";//先将p1和p2的a,b打印出来，方便查看p1.show();cout<<"p2的a,b"<<"   ";p2.show();cout<<"成员函数的+"<<"   ";p3.show();cout<<"+++++++++++++++++++++"<<endl;p3=p1-p2;cout<<"成员函数的-"<<"   ";p3.show();cout<<"+++++++++++++++++++++"<<endl;p3=p1*p2;cout<<"全局函数的乘"<<"   ";p3.show();cout<<"+++++++++++++++++++++"<<endl;p3=p1/p2;cout<<"成员函数的/"<<"   ";p3.show();return 0;
}