Question

c++编程的一道练习题，就是给复数类重载运算符，要求是用友元函数，我编的编译老是有一个error，求改

编码如下：
#include<iostream>using namespace std;class Complex{ double real,image;public: Complex(double r=0.0,double i=0.0){real=r;image=i;} Complex(Complex &com){ real=com.real;image=com.image; } void print(){ cout<<"Real="<<real<<'\t'<<"Image="<<image<<endl; } friend Complex operator-(Complex,Complex); friend Complex operator-=(Complex,Complex); friend Complex operator*=(Complex,Complex); friend Complex operator/=(Complex,Complex); Complex operator++(); Complex operator++(int);};Complex operator-(Complex c1,Complex c2){ Complex temp(c1.real-c2.real,c1.image-c2.image); return temp;}Complex operator -= (Complex c1,Complex c2){ c1.real=c1.real-c2.real; c1.image=c1.image-c2.image; return c1;}Complex Complex::operator /= (Complex c1,Complex c2){ Complex temp; double d=c2.real*c2.real+c2.image*c2.image; temp.real =(c1.real*c2.real+c1.image*c2.image)/d; temp.image =(c1.image*c2.real-c1.real*c2.image)/d; c1.real=temp.real; c2.image=temp.image; return temp;}Complex Complex::operator *= (Complex c1,Complex c2){ Complex temp; temp.real =c1.real*c2.real-c1.image*c2.image; temp.image=c1.image*c2.real+c1.real*c2.image; c1.real=temp.real; c2.image=temp.image; return temp;}Complex Complex::operator ++ (){ return Complex(++real,image);}Complex Complex::operator ++ (int){ return Complex(real++,image);}int main(){ Complex c1(1.0,1.0),c2(2.0,2.0),c3(4.0,4.0),c; c1.print(); c=c2-c3;c.print (); c-=c1;c.print(); c1++;c1.print (); return 0;}

Answer 1

1. 把第一行的<iostream>改为<iostream.h>

2. 把第二行内容去掉

3. 把以下两行中的complex都去掉一个

   Complex Complex::operator /= (Complex c1,Complex c2){

   Complex Complex::operator *= (Complex c1,Complex c2){

4. 最终程序为：

   #include<iostream.h>
   class Complex{
    double real,image;
   public:
    Complex(double r=0.0,double i=0.0){real=r;image=i;}
    Complex(Complex &com){
     real=com.real;image=com.image;
    }
    void print(){
     cout<<"Real="<<real<<'\t'<<"Image="<<image<<endl;
    }
    friend Complex operator-(Complex,Complex);
    friend Complex operator-=(Complex,Complex);
    friend Complex operator*=(Complex,Complex);
    friend Complex operator/=(Complex,Complex);
    Complex operator++();
    Complex operator++(int);
   };
   Complex operator-(Complex c1,Complex c2){
    Complex temp(c1.real-c2.real,c1.image-c2.image);
    return temp;
   }
   Complex operator -= (Complex c1,Complex c2){
    c1.real=c1.real-c2.real;
    c1.image=c1.image-c2.image;
    return c1;
   }
   Complex operator /= (Complex c1,Complex c2){
    Complex temp;
    double d=c2.real*c2.real+c2.image*c2.image;
    temp.real =(c1.real*c2.real+c1.image*c2.image)/d;
    temp.image =(c1.image*c2.real-c1.real*c2.image)/d;
    c1.real=temp.real;
    c2.image=temp.image;
    return temp;
   }
   Complex operator *= (Complex c1,Complex c2){
    Complex temp;
    temp.real =c1.real*c2.real-c1.image*c2.image;
    temp.image=c1.image*c2.real+c1.real*c2.image;
    c1.real=temp.real;
    c2.image=temp.image;
    return temp;
   }
   Complex Complex::operator ++ (){
    return Complex(++real,image);
   }
   Complex Complex::operator ++ (int){
    return Complex(real++,image);
   }
   int main(){
    Complex c1(1.0,1.0),c2(2.0,2.0),c3(4.0,4.0),c;
    c1.print();
    c=c2-c3;c.print ();
    c-=c1;c.print();
    c1++;c1.print ();
    return 0;
   }

Answer 2

1）Complex::operator /= （）不需要加限定符号＝＝》::operator /（）
2）

Complex Complex::operator ++ (){
return Complex(++real,image);
}

实现有问题：
Complex Complex::operator ++ (){
real++;
return *this;
}
最好改成如下的形式：
Complex ＆Complex::operator ++ (){
real++;
return *this;
}