实现负数运算的类
//complex0.h
#include <iostream>
#ifndef COMPLEX0_H_
#define COMPLEX0_H_
class Complex
{
private:
double real;
double image;
public:
Complex();
Complex(double dreal,double dimage=0.0);
~Complex();
friend Complex operator+(const Complex &a,const Complex &b);
friend Complex operator-(const Complex &a,const Complex &b);
friend Complex operator*(const Complex &a,const Complex &b);
friend Complex operator~(const Complex &a);
friend Complex operator*(const Complex &a,double n);
friend Complex operator*(double n,const Complex &a);
friend std::ostream & operator < <(std::ostream &os,const Complex&a);
friend std::istream & operator> > (std::istream &os,const Complex&a);
}
#endif COMPLEX0_H_
//complex0.cpp
#include <iostream>
#include "complex0.h "
Complex::Complex()
{
real=0.0;
image=0.0;
}
Complex::Complex(double dreal,double dimage)
{
real=dreal;
image=dimage;
}
Complex::~Complex(){}
Complex operator+(const Complex &a,const Complex &b)
{
return Complex(a.real+b.real,a.image+b.image);
}
Complex operator-(const Complex &a,const Complex &b)
{
return Complex(a.real-b.real,a.image-b.image);
}
Complex operator*(const Complex &a,const Complex &b)
{
return Complex(a.real*b.real-a.image*b.image,a.real*b.image+a.image*b.real);
}
Complex operator*(const Complex &a,double n)
{
return Complex(a.real*n,a.image*n);
}
Complex operator*(double n,const Complex &a)
{
return a*n;
}
Complex operator~(const Complex &a)
{
return Complex(a.real,-a.image);
}
std::ostream & operator < <(std::ostream &os,const Complex&a)
{
os < < "( " < <a.real < < ", " < <a.image < < "i) ";
return os;
}
std::istream & operator> > (std::istream &is,const Complex&a)
{
std::cout < < "real: ";
is> > a.real;
std::cout < < "imaginary: ";
is> > a.image;
return is;
}
//usecomplex0.cpp
#include <iostream>
using namespace std;
#include "complex0.h "
int main()
{
Complex a(3.0,4.0);
Complex c;
cout < < "Enter a complex number(q to quit) " < <endl;
while(cin> > c)
{
cout < < "c is " < <c < <endl;
cout < < "complex conjugate is " < <~c < <endl;
cout < < "a is " < <a < <endl;
cout < < "a+c is " < <a+c < <endl;
cout < < "a-c is " < <a-c < <endl;
cout < < "a*c is " < <a*c < <endl;
cout < < "2*a is " < <2*a < <endl;
cout < < "Enter a complex number(q to quit) " < <endl;
}
cout < < "Done! " < <endl;
system( "pause ");
return 0;
}
编译的时候会出现
c:\documents and settings\新\my documents\visual studio 2005\projects\zmx\zmx\complex0.cpp(5) : error C2533: 'Complex::{ctor} ' : constructors not allowed a return type
usecomplex0.cpp
c:\documents and settings\新\my documents\visual studio 2005\projects\zmx\zmx\usecomplex0.cpp(4) : error C2628: 'Complex ' followed by 'int ' is illegal (did you forget a '; '?)
c:\documents and settings\新\my documents\visual studio 2005\projects\zmx\zmx\usecomplex0.cpp(5) : error C3874: return type of 'main ' should be 'int ' instead of 'Complex '
这样的三个错误。。。
如果我将实现中的两个构造函数的顺序对调，除了那三个错误之外还会出现很多
error C2264: 'Complex::Complex ' : error in function definition or declaration; function not called 这样的错误
哪儿错了？还有哪儿有待修改？
[解决办法]
//complex0.h
#include <iostream>
#ifndef COMPLEX0_H_
#define COMPLEX0_H_
class Complex
{
private:
double real;
double image;
public:
Complex();
Complex(double dreal,double dimage=0.0);
~Complex();
friend Complex operator+(const Complex &a,const Complex &b);
friend Complex operator-(const Complex &a,const Complex &b);
friend Complex operator*(const Complex &a,const Complex &b);
friend Complex operator~(const Complex &a);
friend Complex operator*(const Complex &a,double n);
friend Complex operator*(double n,const Complex &a);
friend std::ostream & operator < <(std::ostream &os,const Complex&a);
friend std::istream & operator> > (std::istream &os,const Complex&a);
}; //！！这里加个分号
#endif COMPLEX0_H_
