定义一个定义完整的类（是可以当作独立的产品发布，成为众多项目中的“基础工程”）。扩展+、-、*、/运算符的功能，使之能与double型数据进行运算。设Complex c; double d; c+d和

/**Copyright (c) 2016,烟台大学计算机学院*All rights reserved.*文件名称：main.cpp*作    者：郭辉*完成时间：2016年5月23日*版 本 号：v1.0**问题描述：定义一个定义完整的类（是可以当作独立的产品发布，成为众多项目中的“基础工程”）。扩展+、-、*、/运算符的功能，使之能与double型数据进行运算。设Complex c; double d; c+d和d+c的结果为“将d视为实部为d的复数同c相加”，其他-、*、/运算符类似*输入描述：无。*程序输出：复数的加减乘除。*/#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+(Complex &c1, Complex &c2);    friend Complex operator+(double d1, Complex &c2);    friend Complex operator+(Complex &c1, double d2);    friend Complex operator-(Complex &c1, Complex &c2);    friend Complex operator-(double d1, Complex &c2);    friend Complex operator-(Complex &c1, double d2);    friend Complex operator*(Complex &c1, Complex &c2);    friend Complex operator*(double d1, Complex &c2);    friend Complex operator*(Complex &c1, double d2);    friend Complex operator/(Complex &c1, Complex &c2);    friend Complex operator/(double d1, Complex &c2);    friend Complex operator/(Complex &c1, double d2);    void display();private:    double real;    double imag;};//复数相加：(a+bi)+(c+di)=(a+c)+(b+d)i.Complex operator+(Complex &c1, Complex &c2){    Complex c;    c.real=c1.real+c2.real;    c.imag=c1.imag+c2.imag;    return c;}Complex operator+(double d1, Complex &c2){    Complex c(d1,0);    return c+c2; //按运算法则计算的确可以，但充分利用已经定义好的代码，既省人力，也避免引入新的错误，但可能机器的效率会不佳}Complex operator+(Complex &c1, double d2){    Complex c(d2,0);    return c1+c;}//复数相减：(a+bi)-(c+di)=(a-c)+(b-d)i.Complex operator-(Complex &c1, Complex &c2){    Complex c;    c.real=c1.real-c2.real;    c.imag=c1.imag-c2.imag;    return c;}Complex operator-(double d1, Complex &c2){    Complex c(d1,0);    return c-c2;}Complex operator-(Complex &c1, double d2){    Complex c(d2,0);    return c1-c;}//复数相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i.Complex operator*(Complex &c1, Complex &c2){    Complex c;    c.real=c1.real*c2.real-c1.imag*c2.imag;    c.imag=c1.imag*c2.real+c1.real*c2.imag;    return c;}Complex operator*(double d1, Complex &c2){    Complex c(d1,0);    return c*c2;}Complex operator*(Complex &c1, double d2){    Complex c(d2,0);    return c1*c;}//复数相除：(a+bi)/(c+di)=(ac+bd)/(c^2+d^2) +(bc-ad)/(c^2+d^2)iComplex operator/(Complex &c1, 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;}Complex operator/(double d1, Complex &c2){    Complex c(d1,0);    return c/c2;}Complex operator/(Complex &c1, double d2){    Complex c(d2,0);    return c1/c;}void Complex::display(){    cout<<"("<<real<<","<<imag<<"i)"<<endl;}int main(){    Complex c1(3,4),c2(5,-10),c3;    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：

<img src="http://img.blog.csdn.net/20160523223725208" alt="" />

心得：

成员函数和友元函数的区分