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 Person
{
    friend  const Person operator-(const Person &L,const Person &R);
private:
    int a;
    int b;
public:
    Person() {}
    Person(int a,int b):a(a),b(b){}

    //成员函数实现运算符+重载
    const Person operator+(const Person &R) const    //L+R
    {
        Person temp;
        temp.a = a + R.a;
        temp.b = b + R.b;
        return temp;
    }
    void show()
    {
        cout << "a = " << a << " b = " << b << endl;
    }
};

//全局函数实现运算符-重载
const Person operator-(const Person &L,const Person &R)   //L-R
{
    Person temp;
    temp.a = L.a - R.a;
    temp.b = L.b - R.b;
    return temp;
}
int main()
{
    Person p1(1,2);
    Person p2(2,1);
    Person p3 = p1.operator+(p2);  //+重载
    p3.show();
    Person p4 = operator-(p1,p2);  //-重载
    p4.show();
    return 0;

思维导图