第八周上机实践项目1-实现复数类中的运算符重载（友元函数）

梦里梦外; 2022-08-08 00:52 165阅读 0赞

/*
     *Copyright  (c)  2014,烟台大学计算机学院
     *All rights reserved.
     *文件名称: test.cpp
     *作        者:满星辰
     *完成日期:2015 年 4 月 28 日
     *版本号:v1.0
     *
     *问题描述:请用类的友元函数，而不是成员函数，再次完成定义复数类重载运算符+、-、*、/，使之能用于复数的加减乘除；
     *输入描述:
     *程序输出:
     */
    #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
    void Complex::display()
    {
        cout<<"("<<real<<","<<imag<<"i"<<")"<<endl;
    }
    Complex operator+(const Complex &c1,const Complex &c2)
    {
        Complex c;
        c.real=c1.real+c2.real;
        c.imag=c1.imag+c2.imag;
        return c;
    }
    Complex operator-(const Complex &c1,const Complex &c2)
    {
        Complex c;
        c.real=c1.real-c2.real;
        c.imag=c2.imag-c2.imag;
        return c;
    }
    Complex operator * (const Complex &c1,const Complex &c2)
    {
        Complex c;
        c.real=c1.real*c2.real-c1.imag*c2.imag;
        c.imag=c1.real*c2.imag+c1.imag*c2.real;
        return c;
    }
    Complex operator / (const Complex &c1,const Complex &c2)
    {
        Complex c;
        c.real=(c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
        c.imag=(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
        return c;
    }
    //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;
    }

图片：

![Center][]  
心得：

一开始我想的过于简单，只在类内声明时在函数前面加个friend 再在函数定义时把Complex::去掉。。。

然后就报错。。。看错误才想起这是友元函数，没有\*this指针，需要两个参数才能实现两个数之间的关系

[Center]: /images/20220805/d21479ffb01b40f185a0f4218acac0ca.png