C++完成複數類的運算符重載

                                     複數類的運算符重載      運算符重載指對已有的運算符重新進行定義，賦予其另一種功能，以适應不同的資料類型      對于複數類，有實部和虛部兩部分，是以我們對于+，-，*，/，要列式計算。      如要加上+=，-+，*=，/=也會很容易。 程式如下：

#include<iostream>
using namespace std;

class Complex
{
public:
	Complex(double real = 0.0, double image = 0.0);       //聲明構造函數時指定預設參數

	Complex& operator=(const Complex& c);
	Complex operator+(const Complex& c);
	Complex operator-(const Complex& c);
	Complex operator*(const Complex& c);
	Complex operator/(const Complex& c);

	void display();

private:
	double _real;
	double _image;
};
//定義構造函數
Complex::Complex(double real, double image)
{
	_real = real;
	_image = image;
}

//複數指派
Complex& Complex::operator=(const Complex& c)
{
	if (this != &c)
	{
		_real = c._real;
		_image = c._image;
	}
	return *this;
}

//複數相加
Complex Complex::operator+(const Complex& c)
{
	Complex c1;
	c1._real = _real + c._real;
	c1._image = _image + c._image;
	return c1;
}

//複數相減
Complex Complex::operator-(const Complex& c)
{
	Complex c1;
	c1._real = _real - c._real;
	c1._image = _image - c._image;
	return c1;
}

//複數相乘(a+bi)*(c+di)
Complex Complex::operator*(const Complex& c)
{
	Complex c1;
	c1._real = _real*c._real - _image*c._image;
	c1._image = _image*c._real + _real*c._image;
	return c1;
}

//複數相除(a+bi)/(c+di)
Complex Complex::operator/(const Complex& c)
{
	Complex c1;
	c1._real = (_real*c._real + _image*c._image) / (c._real*c._real + c._image*c._image);
	c1._image = (_image*c._real - _real*c._image) / (c._real*c._real + c._image*c._image);
	return c1;
}

void Complex::display()
{
	cout << "(" << _real << "," << _image << ")" << endl;
}

void test()
{
	Complex c1(1.0, 2.0);
	Complex c2(4.0, 5.0);
	Complex c3;

	c3 = c1.operator+(c2);
	c3.display();

	c3 = c1.operator-(c2);
	c3.display();

	c3 = c1.operator*(c2);
	c3.display();

	c3 = c1.operator/(c2);
	c3.display();

	c2 = c1.operator=(c1);
	c2.display();
}

int main()
{
	test();
	system("pause");
	return 0;
}
           

在此基礎上，就可以直接利用已重載好的運算符來重載+=，-=，*=，/= 程式如下：

//複數加等(a+bi)=(a+bi)+(c+di)
void Complex:: operator+=(const Complex& c)
{
	*this=*this+c;

	/*_real += c._real;
	_image += c._image;*/
}

//複數減等(a+bi)=(a+bi)-(c+di)
void Complex:: operator-=(const Complex& c)
{
	*this = *this - c;

	/*_real -= c._real;
	_image -= c._image;*/
}

//複數乘等(a+bi)=(a+bi)*(c+di)
void Complex:: operator*=(const Complex& c)
{
	*this = *this*c;
}

//複數除等(a+bi)=(a+bi)/(c+di)
void Complex::operator/=(const Complex& c)
{
	*this = *this / c;
}

void Complex::display()
{
	cout << "(" << _real << "," << _image << ")" << endl;
}

void test2()
{
	Complex c1(1.0, 2.0);
	Complex c2(4.0, 5.0);

	c1+=c2;
	c1.display();

	c1-=(c2);
	c1.display();

	c1*=(c2);
	c1.display();

	c1/=(c2);
	c1.display();
}
           

運作結果如下，讀者可自行驗證。