运算符重载的方法

运算符重载的方法是定义一个重载运算符的函数，在需要执行被重载的运算符时，系统自动调用该函数，以实现相应的运算。运算符重载实质是函数的重载

重载运算符的函数格式如下：

函数类型 operator 运算符名称（形参列表）

{对运算符的重载处理}

例1 重载运算符“+”，使之能用于两个复数相加

#include "stdafx.h"
#include<iostream>
using namespace std;
class Complex
{
public:
 Complex()
 {
  real=0;
  imag=0;
 }
 Complex(double r,double i){real=r;imag=i;}
 Complex Complex::operator+(Complex &c2);
 void display();
private:
 double real;
 double imag;
};
Complex Complex::operator+(Complex &c2) // 定义重载运算符+的函数
{
 Complex c;
 c.real=real+c2.real;
 c.imag=imag+c2.imag;
 return c;
}
void Complex::display()
{
 cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

int _tmain(int argc, _TCHAR* argv[])
{ 
 Complex c1(1,3),c2(7,-6),c3;
 c3=c1+c2;
 cout<<"c1=";c1.display();
 cout<<"c2=";c2.display();
 cout<<"c3=";c3.display();
 return 0;
}

 

也可将运算符重载函数作为友元函数

#include "stdafx.h"
#include<iostream>
using namespace std;
class Complex
{
public:
 Complex()
 {
  real=0;
  imag=0;
 }
 Complex(double r,double i){real=r;imag=i;}
 friend Complex operator+(Complex &c1,Complex &c2);
 void display();
private:
 double real;
 double imag;
};
Complex operator+(Complex &c1,Complex &c2)
{
 return Complex(c1.real+c2.real,c1.imag+c2.imag);
}
void Complex::display()
{
 cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

int _tmain(int argc, _TCHAR* argv[])
{ 
 Complex c1(1,3),c2(7,-6),c3;
 c3=c1+c2;
 cout<<"c1=";c1.display();
 cout<<"c2=";c2.display();
 cout<<"c3=";c3.display();
 return 0;
}