实现完整的类运算

/** 程序的版权和版本声明部分* Copyright (c)2013, 烟台大学计算机学院学生* All rightsreserved.* 文件名称：a.cpp* 作    者：孔云* 完成日期：2014年4月16日* 版 本 号： v1.0* 输入描述：主函数中给出* 问题描述：用类的友元函数及成员函数，定义完整的类重载运算符+、-、*、/，使之能用于实复数的加减乘除。* 输出描述：四则运算后的结果*/#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 &c2,Complex &c3);    Complex operator+(double);    friend Complex operator+(double,Complex &c2);    friend Complex operator-(Complex &c2,Complex &c3);    Complex operator-(double);    friend Complex operator-(double,Complex &c2);    friend Complex operator*(Complex &c2,Complex &c3);    friend Complex operator*(double,Complex &c3);    Complex operator*(double);    friend  Complex operator/(Complex &c2,Complex &c3);    friend Complex operator/(double,Complex &c3);    Complex operator/(double);    double friend add(Complex &);    double friend reduce(Complex &);    double friend multiply(Complex &);    double friend divide(Complex &);    void display1();    void display2();private:    double real;    double imag;};//下面定义成员函数void Complex::display1(){    cout<<"("<<real<<","<<imag<<"i)"<<endl;}void Complex::display2(){    Complex b(2.45,2.36);    cout<<"两个实数和:"<<add(b)<<endl;    cout<<"两个实数差:"<<reduce(b)<<endl;    cout<<"两个实数积:"<<multiply(b)<<endl;    cout<<"两个实数商:"<<divide(b)<<endl;}Complex operator+(Complex &c2,Complex &c3){    return Complex(c2.real+c3.real,c2.imag+c3.imag);}Complex operator-(Complex &c2,Complex &c3){    return Complex(c2.real-c3.real,c2.imag-c3.imag);}Complex operator*(Complex &c2,Complex &c3){    return Complex(c3.real*c2.real-c3.imag*c2.imag,c3.imag*c2.real+c3.real*c2.imag);}Complex operator/(Complex &c2,Complex &c3){    int k=c3.real*c3.real+c3.imag*c3.imag;    return Complex((c2.real*c3.real-c2.imag*c3.imag)/k,(c2.imag*c3.real+c2.real*c3.imag)/k);}Complex Complex::operator+(double p1){    Complex a;    a.real=real+p1;    a.imag=imag;    return a;}Complex operator+(double p2,Complex &c2){    return Complex(c2.real+p2,c2.imag);}Complex Complex::operator-(double p3){    Complex b;    b.real=real-p3;    b.imag=imag;    return b;}Complex operator-(double p4,Complex &c2){    return Complex(p4-c2.real,-c2.imag);}Complex Complex::operator*(double h1){    Complex c;    c.real=real*h1;    c.imag=imag*h1;    return c;}Complex operator*(double h2,Complex &c2){    return Complex(h2*c2.real,h2*c2.imag);}Complex operator/(double h3,Complex &c3){    int g=c3.real*c3.real+c3.imag*c3.imag;    return  Complex(h3*c3.real/g,-h3*c3.imag/g);}Complex Complex::operator/(double h4){    Complex d;    d.real=real/h4;    d.imag=imag/h4;    return d;}double add(Complex &c2){    return(c2.real+c2.imag);}double reduce(Complex &c2){    return(c2.real-c2.imag);}double multiply(Complex &c2){    return(c2.real*c2.imag);}double divide(Complex &c2){    return(c2.real/c2.imag);}//下面定义用于测试的main()函数int main(){    Complex c1(3,4),c2(5,-10),c3,c4(2.56,0);    cout<<"c1=";    c1.display1();    cout<<"c2=";    c2.display1();    c3=c1+c2;    cout<<"c1+c2=";    c3.display1();    c3=c1-c2;    cout<<"c1-c2=";    c3.display1();    c3=c1*c2;    cout<<"c1*c2=";    c3.display1();    c3=c1/c2;    cout<<"c1/c2=";    c3.display1();    c3=c1+c4;    cout<<"c1+c4=";    c3.display1();    c3=c4+c2;    cout<<"c4+c2=";    c3.display1();    c3=c1-c4;    cout<<"c1-c4=";    c3.display1();    c3=c4-c2;    cout<<"c4-c2=";    c3.display1();    c3=c1*c4;    cout<<"c1×c4=";    c3.display1();    c3=c4*c2;    cout<<"c4×c2=";    c3.display1();    c3=c1/c4;    cout<<"c1÷c4=";    c3.display1();    c3=c4/c2;    cout<<"c4÷c1=";    c3.display1();    c3.display2();    return 0;}

心得体会：在此程序中，在实现复数加实数的函数中，默认第一个参数为类对象，仅含有一个实数参数。然而，尽管形参的顺序任意，不要求第一个参数为类对象，但值得注意的是：在运用运算符的表达式中，要求运算符左侧的操作数与函数第一个对应，运算符右侧的操作数与函数的第二个参数对应。这在实现实数加复数的函数中体现到。