第八号走上机实践项目1——实现复数类中的运算符重载（2）

用类的友元函数

问题及代码

/*
 * Copyright (c) 2015, 烟台大学计算机学院
 * All rights reserved.
 * 文件名称：test.cpp
 * 作    者：辛彬
 * 完成日期：2015 年 4 月 26 日
 * 版 本 号：v1.0
 */
#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+(const Complex &c1,const Complex &c2);
    friend Complex operator-(const Complex &c1,const Complex &c2);
    friend Complex operator*(const Complex &c1,const Complex &c2);
    friend Complex operator/(const Complex &c1,const Complex &c2);
    void display();
private:
    double real;
    double imag;
};
//下面定义成员函数
Complex operator+(const Complex &c1,const Complex &c2)
{
    return Complex(c1.real+c2.real,c1.imag+c2.imag);
}
Complex operator-(const Complex &c1,const Complex &c2)
{
    return Complex(c1.real-c2.real,c1.imag+c2.imag);
}
Complex operator*(const Complex &c1,const Complex &c2)
{
    return Complex(c1.real*c2.real-c1.imag*c2.imag,c1.imag*c2.real+c1.real*c2.imag);
}
Complex operator/(const Complex &c1,const Complex &c2)
{
    return Complex((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}
void Complex::display()
{
    if(imag>0)
        cout<<real<<"+"<<imag<<"i"<<endl;
    else
        cout<<real<<imag<<"i"<<endl;
}
//下面定义用于测试的main()函数
int main()
{
    Complex c1(3,4),c2(5,-10),c3;
    cout<<"c1=";
    c1.display();
    cout<<"c2=";
    c2.display();
    c3=c1+c2;
    cout<<"c1+c2=";
    c3.display();
    c3=c1-c2;
    cout<<"c1-c2=";
    c3.display();
    c3=c1*c2;
    cout<<"c1*c2=";
    c3.display();
    c3=c1/c2;
    cout<<"c1/c2=";
    c3.display();
    return 0;
}

运行结果：