第八周 【项目1-实现复数类中的运算符重载】友元函数

问题描述：

（1）请用类的成员函数，定义复数类重载运算符+、-、*、/，使之能用于复数的加减乘除

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1. class Complex   
2. {  
3. public:  
4.     Complex(){real=0;imag=0;}  
5.     Complex(double r,double i){real=r; imag=i;}  
6.     Complex operator+(const Complex &c2);  
7.     Complex operator-(const Complex &c2);  
8.     Complex operator*(const Complex &c2);  
9.     Complex operator/(const Complex &c2);  
10.     void display();  
11. private:  
12.     double real;  
13.     double imag;  
14. };  
15. //下面定义成员函数  
16.   
17.   
18. //下面定义用于测试的main()函数  
19. int main()  
20. {  
21.     Complex c1(3,4),c2(5,-10),c3;  
22.     cout<<"c1=";  
23.     c1.display();  
24.     cout<<"c2=";  
25.     c2.display();  
26.     c3=c1+c2;  
27.     cout<<"c1+c2=";  
28.     c3.display();  
29.     c3=c1-c2;  
30.     cout<<"c1-c2=";  
31.     c3.display();  
32.     c3=c1*c2;  
33.     cout<<"c1*c2=";  
34.     c3.display();  
35.     c3=c1/c2;  
36.     cout<<"c1/c2=";  
37.     c3.display();  
38.     return 0;  
39. }  

（2）请用类的友元函数，而不是成员函数，再次完成上面提及的运算符的重载；

代码：

#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-(Complex &c1, Complex &c2);    friend Complex operator*(Complex &c1, Complex &c2);    friend Complex operator/(Complex &c1, Complex &c2);    void display();private:    double real;    double imag;};Complex operator+(Complex &c1, Complex &c2){    Complex c;    c.real=c1.real+c2.real;    c.imag=c1.imag+c2.imag;    return c;}Complex operator-(Complex &c1, Complex &c2){    Complex c;    c.real=c1.real-c2.real;    c.imag=c1.imag-c2.imag;    return c;}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/(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;}void Complex::display(){    cout<<real<<"+"<<imag<<"i\n";}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：