【C++】复数的运算符重载

运算符重载的定义：

用户对于自定义类型的运算操作，例如复数的运算。需要重新定义运算符号（创建函数）。

除了类属关系运算符"."、成员指针运算符".*"、作用域运算符"::"、sizeof运算符和三目运算符"?:"以外，C++中的所有运算符都可以重载。

复数的运算符重载如下：

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#include<iostream>
#include<string>
using namespace std;

class Complex;
Complex operator+(int x, Complex &c);
ostream& operator<<(ostream &out, const Complex &c);
istream& operator>>(istream &in, Complex &c);

class Complex
{
friend istream& operator>>(istream &in, Complex &c);
friend ostream& operator<<(ostream &out, const Complex &c);
friend Complex operator+(int x, Complex &c);
public:
Complex(const int real = 0, const int imag = 0) :m_real(real), m_imag(imag)
{}
~Complex()
{}
void Show()const
{
cout << "(" << m_real << "," << m_imag << ")" << endl;
}

public:
Complex operator+(int x)
{
return Complex(m_real + x, m_imag);
}
Complex operator+(Complex &c)
{
return Complex(m_real + c.m_real, m_imag + c.m_imag);
}

Complex operator-(Complex &c)
{
return Complex(m_real - c.m_real, m_imag - c.m_imag);
}

friend Complex operator+(int x, Complex &c)
{
return Complex(x + c.m_real, c.m_imag);
}

friend Complex operator-(int x, Complex &c)
{
return Complex(x - c.m_real, -c.m_imag);
}

Complex operator*(Complex &c);
friend Complex operator*(int x, Complex &c);
Complex operator/(Complex &c);
friend Complex operator/(int x, Complex &c);
Complex operator+=(Complex &c);
Complex operator-=(Complex &c);
Complex operator*=(Complex &c);
Complex operator/=(Complex &c);

private:
int m_real;
int m_imag;
};

Complex Complex::operator/(Complex &c)
{
Complex temp;

temp.m_real = (m_real*c.m_real + m_imag*c.m_imag) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
temp.m_imag = (m_imag*c.m_real - m_real*c.m_imag) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
return temp;
}

Complex operator/(int x, Complex &c)
{
Complex temp;

temp.m_real = (x*c.m_real) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
temp.m_imag = (-x*c.m_imag) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
return temp;
}

Complex Complex:: operator+=(Complex &c)
{
m_real = m_real + c.m_real;
m_imag = m_imag + c.m_imag;
return *this;
}

Complex Complex::operator-=(Complex &c)
{
m_real = m_real - c.m_real;
m_imag = m_imag - c.m_imag;
return *this;
}

Complex Complex:: operator*(Complex &c)
{
return Complex(m_real*c.m_real - m_imag*c.m_imag, m_imag*c.m_real + m_real*c.m_imag);
}

Complex operator*(int x, Complex &c)
{
return Complex(c.m_real*x, c.m_imag*x);
}

Complex Complex::operator*=(Complex &c)
{
int i = m_real;
m_real = m_real*c.m_real - m_imag*c.m_imag;
m_imag = m_imag*c.m_real + i*c.m_imag;
return *this;
}

Complex Complex:: operator/=(Complex &c)
{

m_real = (m_real*c.m_real + m_imag*c.m_imag) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
m_imag = (m_imag*c.m_real - m_real*c.m_imag) / (c.m_real*c.m_real + c.m_imag*c.m_imag);
return *this;
}
ostream& operator<<(ostream &out, const Complex &c)
{
out << "(" << c.m_real << "," << c.m_imag << ")";
return out;
}

istream& operator>>(istream &in, Complex &c)
{
in >> c.m_real >> c.m_imag;
return in;
}

int main()
{
Complex c1(2, 1);
Complex c2(3, 2);

Complex c;

c = c1 + c2;
cout<<c1<<"+"<<c2<<"="<<c<<endl;

c = c1 * c2;
cout << c1 << "*" << c2 << "=" << c << endl;

c = c1 / c2;
cout << c1 << "*" << c2 << "=" << c << endl;

c = 2 + c1;
cout <<"2"<< "+" << c1 << "=" << c << endl;
//    c1+=c2;
//    cout<<c1<<endl;
//    c1-=c2;
//    cout<<c1<<endl;
c1 *= c2;
cout << c1 << endl;
c1 /= c2;
cout << c1 << endl;

c = 4 / c1;
cout << c << endl;
Complex c3;
cin>>c3;
cout<<c3;
return 0;
}

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运行结果：