zhiyinjixu总结：运算符重载的两种分类

运算符重载的两种分类：
一、作为类成员

#include <iostream>
using namespace std;

class complex
{
public:
 complex (){}
 complex (int x, int y)  {real = x; imag = y;}
public:
 void display ();
private: 
 int real;
 int imag;
public :
 complex operator+ (complex& ob2);
};

complex complex::operator+ (complex& ob2)       //以c2为实参调用c1的运算符重载函数
{
complex temp ;
temp.real = real + ob2.real;
temp.imag = imag + ob2.imag; 
return temp;
}

void complex::display()
{
cout<<real <<"+"<<imag<<"i";
}

 

int main ()
{
 complex ob1(1,5),ob2(6,5),ob3;
 ob3 = ob1 + ob2;
 ob3.display(); 
}

二、作为全局运算符——友元

#include <iostream>
using namespace std;

class complex
{
public:
 complex (){}
 complex (int x, int y)  {real = x; imag = y;}
public:
 void display ();
private: 
 int real;
 int imag;
 friend complex operator+ (complex& ob1,complex ob2);    //运算符重载，作为全局函数——友元
};

void complex::display()
{
cout<<real <<"+"<<imag<<"i";
}

complex operator+ (complex& ob1,complex ob2)
{
complex temp;
temp.real = ob1.real + ob2.real;
temp.imag = ob1.imag + ob2.imag; 
return temp;
}


int main ()
{
 complex ob1(2,5);
 complex ob2(3,8);
 complex ob3;
 ob3 = ob1 + ob2;
 ob3.display(); 
}