第九周 项目一

【项目1-复数类中的运算符重载（续）】
在复数类中的运算符重载基础上

（1）再定义一目运算符 -，-c相当于0-c。

/**Copyright (c)2014,烟台大学计算机与控制工程学院*All rights reserved.*dood luck*文件名称：d.cpp*作    者：张旺华*完成日期：2015年4月29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;    }     Complex operator-();    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);    friend Complex operator+(const double &b,const Complex &c2);    friend Complex operator-(const double &b,const Complex &c2);    friend Complex operator*(const double &b,const Complex &c2);    friend Complex operator/(const double &b,const Complex &c2);    friend Complex operator+(const Complex &c1,const double &b);    friend Complex operator-(const Complex &c1,const double &b);    friend Complex operator*(const Complex &c1,const double &b);    friend Complex operator/(const Complex &c1,const double &b);    void display();private:    double real;    double imag;};//下面定义成员函数 Complex Complex::operator-() {     Complex p(-real,imag);     return p; }Complex operator+(const double &b,const Complex &c2){    Complex c(b,0);    return c+c2;}Complex operator-(const double &b,const Complex &c2){    Complex c(b,0);    return c-c2;}Complex operator*(const double &b,const Complex &c2){    Complex c(b,0);    return c*c2;}Complex operator/(const double &b,const Complex &c2){    Complex c(b,0);    return c/c2;}Complex operator+(const Complex &c1,const double &b){    Complex c(b,0);    return c1+c;}Complex operator-(const Complex &c1,const double &b){    Complex c(b,0);    return c1-c;}Complex operator*(const Complex &c1,const double &b){    Complex c(b,0);    return c1*c;}Complex operator/(const Complex &c1,const double &b){    Complex c(b,0);    return c1/c;}void Complex ::display(){    cout<<"("<<real<<","<<imag<<")"<<endl;}Complex operator+(const Complex &c1,const Complex &c2){    Complex a;    a.real=c1.real+c2.real;    a.imag=c1.imag+c2.imag;    return a;}Complex operator-(const Complex &c1,const Complex &c2){    Complex a;    a.real=c1.real-c2.real;    a.imag=c1.imag-c2.imag;    return a;}Complex operator*(const Complex &c1,const Complex &c2){    Complex a;    a.real=c1.real*c2.real+c1.imag*c2.imag;    a.imag=c1.imag+c2.real+c1.real*c2.imag;    return a;}Complex operator/(const Complex &c1,const Complex &c2){    Complex a;    double k;    k=1/(c2.real*c2.real+c2.imag*c2.imag);    a.real=(c1.real*c2.real+c1.imag*c2.imag)*k;    a.imag=(c1.imag+c2.real-c1.real*c2.imag)*k;    return a;}//下面定义用于测试的main()函数int main(){     Complex c1(3,4),c2(5,-10),c3;     c3=-c1;     c3.display();    double d=11;    cout<<"c1=";    c1.display();    cout<<"c2=";    c2.display();    cout<<"d="<<d<<endl<<endl;    cout<<"下面是重载运算符的计算结果: "<<endl;    c3=c1+c2;    cout<<"c1+c2=";    c3.display();    cout<<"c1+d=";    (c1+d).display();    cout<<"d+c1=";    (d+c1).display();    c3=c1-c2;    cout<<"c1-c2=";    c3.display();    cout<<"c1-d=";    (c1-d).display();    cout<<"d-c1=";    (d-c1).display();    c3=c1*c2;    cout<<"c1*c2=";    c3.display();    cout<<"c1*d=";    (c1*d).display();    cout<<"d*c1=";    (d*c1).display();    c3=c1/c2;    cout<<"c1/c2=";    c3.display();    cout<<"c1/d=";    (c1/d).display();    cout<<"d/c1=";    (d/c1).display();    return 0;}

运行结果：

 学习心得： 就是不太清楚为什么我用friend 就不行了，好像一定要用成员函数