友元运算符重载函数

#include<iostream>
using namespace std;
class Complex
{
public:
	Complex();	//默认构造函数
	Complex(double, double);	//定义带有参数的构造函数
	friend Complex operator+(Complex& ,Complex &);	//友元运算符重载函数
	void display();	//声明输出函数
private:
	double real;	//实部
	double imag;	//虚部
};

Complex::Complex()	
{
	real = 0;
	imag = 0;
}

Complex::Complex(double r, double i)
{
	real = r;
	imag = i;
}
Complex operator+(Complex& c2,Complex &c1) {	//定义全局函数
	Complex c;
	c.real = c2.real + c1.real;
	c.imag = c2.imag + c1.imag;
	return c;
}
/*   这是不使用对运算符重载的方法  实现2个复数的相加
	Complex Complex::Complex_add(Complex& c2)
{
	Complex c;
	c.real = c2.real + this->real;
	c.imag = c2.imag + this->imag;
	return c ;
}
*/

//Complex Complex::operator+(Complex& c2)	//使用运算符重载 对+  进行实现2个复数的相加
//{
//	Complex c;
//	c.real = c2.real + this->real;
//	c.imag = c2.imag + this->imag;
//	return c;
//	
//}

void Complex::display()
{
	cout << "(" << real << "," << imag << "i" << ")"<<endl;
}

int main()
{
	Complex c1(3, 4), c2(5, -10), c3;
	c3 = c1 + c2;
	cout << "c1 = ";
	c1.display();
	cout << "c2 = ";
	c2.display();
	cout << "c1+c2=";
	c3.display();
	return 0;
}