复数类加减法运算重载---成员函数形式

#include <iostream>

using namespace std;

class complex       //复数类定义
{
public:
complex(double r=0.0,double i=0.0)  //构造函数
{
real=r;
imag=i;
}
complex operator + (complex c2);    //运算符+重载成员函数
complex operator - (complex c2);    //运算符-重载成员函数
void display();                     //输出复数
private:
double real;                        //复数实部
double imag;                        //复数虚部
};
complex complex::operator + (complex c2)   //重载实现
{
return complex(real+c2.real,imag+c2.imag);
}
complex complex::operator - (complex c2)   //重载实现
{
return complex(real-c2.real,imag-c2.imag);
}
void complex::display()
{
cout<<"("<<real<<","<<imag<<")"<<endl;
}

int main()
{
complex c1(5,4),c2(2,10),c3;
cout<<"c1=";
c1.display();
cout<<"c2=";
c2.display();
c3=c1-c2;
cout<<"c3=c1-c2=";
c3.display();
c3=c1+c2;
cout<<"c3=c1+c2=";
c3.display();
return 0;
}