溫暖午後的金針田__孕育有趣的創新

以複數相加相乘為例，input兩個複數，output運算結果

Operator overloading，兩個方法：1、friend function 2、member function

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

class ComplexNumber
{
    friend ostream &operator<<( ostream &, ComplexNumber & );

public:
    ComplexNumber(int _real, int _imagin)
    {
        real = _real;
        imagin = _imagin;
    }
    ComplexNumber(){}

    ComplexNumber &operator+(ComplexNumber &c)
    {
        ComplexNumber *tmp;
        tmp->real = real + c.real;
        tmp->imagin = imagin + c.imagin;
        return *tmp;
    }

    ComplexNumber &operator*(ComplexNumber &c)
    {
        ComplexNumber *tmp;
        tmp->real = (real * c.real) - (imagin * c.imagin);
        tmp->imagin = ((real * (c.imagin)) + (imagin * (c.real)));
        return *tmp;
    }

private:
    int real;
    int imagin;
};

ostream &operator<<( ostream &out, ComplexNumber &number )
{
    out << number.real << " +(" << number.imagin << ")i" << endl;
    return out;
}

int main()
{
    int a,b,c,d;
    cout<< "key in the real number of complex: "<<endl;
    cin>>a;
    cout<< "key in the imaginary number of complex: "<<endl;
    cin>>b;
    ComplexNumber obj01(a,b);
    cout<< "key in the real number of complex: "<<endl;
    cin>>c;
    cout<< "key in the imaginary number of complex: "<<endl;
    cin>>d;
    ComplexNumber obj02(c,d);

    ComplexNumber add,mult;
    add = obj01 + obj02;
    mult = obj01 * obj02;
    cout<<"Addition: "<<add;
    cout<<"multiplication: "<<mult;
    return 0;
}
/**(a+bi)+(c+di) = (a+c)+(b+d)i**/
/**(a+bi)*(c+di) = (ac-bd)+(ad+bc)i**/