operator+ overload example

complex.cpp

class MyComplex
{
private:
	double real, imag;
public:
	MyComplex(){
		real = 0; 
		imag = 0;
	}

	MyComplex(double r, double i) {
		real = r;
		imag = i;
	}

	double getReal() const {
		return real;
	}

	double getImag() const {
		return imag;
	}

	MyComplex & operator=(const MyComplex &);
	
	friend const 
		MyComplex operator+(const MyComplex&, const MyComplex&); 
};

MyComplex & MyComplex::operator=(const MyComplex& c) {
	real = c.real;
	imag = c.imag;
	return *this;
}

/* This is not a member function of MyComplex class */
const MyComplex operator+(const MyComplex& c1, const MyComplex& c2) {
	MyComplex temp;
	temp.real = c1.real + c2.real;
	temp.imag = c1.imag + c2.imag;
	return temp;
}

#include <iostream>

int main()
{
	using namespace std;

	MyComplex c1(5,10);
	MyComplex c2(50,100);
	cout << "c1= " << c1.getReal() << "+" << c1.getImag() << "i" << endl;
	cout << "c2= " << c2.getReal() << "+" << c2.getImag() << "i" << endl;
	c2 = c1;
	cout << "assign c1 to c2:" << endl; 
	cout << "c2= " << c2.getReal() << "+" << c2.getImag() << "i" << endl;
	cout << endl;

	MyComplex c3(10,100);
	MyComplex c4(20,200);
	cout << "c3= " << c3.getReal() << "+" << c3.getImag() << "i" << endl;
	cout << "c4= " << c4.getReal() << "+" << c4.getImag() << "i" << endl;
	MyComplex c5 = c3 + c4;
	cout << "adding c3 and c4" << endl;
	cout << "c3= " << c3.getReal() << "+" << c3.getImag() << "i" << endl;
	cout << "c4= " << c4.getReal() << "+" << c4.getImag() << "i" << endl;
	cout << "c5= " << c5.getReal() << "+" << c5.getImag() << "i" << endl;
}