C++语言基础 例程 运算符重载的方法

贺老师的教学链接  本课讲解

以复数的加法为例：用成员函数实现复数加法

#include <iostream>using namespace std;
class Complex
{
public:
    Complex( )
    {
        real=0;
        imag=0;
    }
    Complex(double r,double i)
    {
        real=r;
        imag=i;
    }
    Complex add(Complex &c2);
    void display( );
private:
    double real;
    double imag;
};
Complex Complex::add(Complex &c2)
{
    Complex c;
    c.real=real+c2.real;
    c.imag=imag+c2.imag;
    return c;
}

void Complex::display( )
{
    cout<<"("<<real<<","<<imag<<"i)"<<endl;
}

int main( )
{
    Complex c1(3,4),c2(5,-10),c3;
    cout<<"c1=";
    c1.display( );
    cout<<"c2=";
    c2.display( );
    c3=c1.add(c2);
    cout<<"c1+c2=";
    c3.display( );
    return 0;
}

运算符重载的方法

#include <iostream>using namespace std;class Complex{public:    Complex( )    {        real=0;        imag=0;    }    Complex(double r,double i)    {        real=r;        imag=i;    }    Complex operator+(Complex &c2);    void display( );private:    double real;    double imag;};Complex Complex::operator+(Complex &c2){    Complex c;    c.real=real+c2.real;    c.imag=imag+c2.imag;    return c;} void Complex::display( ){    cout<<"("<<real<<","<<imag<<"i)"<<endl;} int main( ){    Complex c1(3,4),c2(5,-10),c3,c4;        cout<<"c1=";    c1.display( );    cout<<"c2=";    c2.display( );    c3=c1+c2;  //c3=c1.operator+(c2);    cout<<"c1+c2=";    c3.display( );    return 0;}

实现operator+=(Complex &c2)?

#include <iostream>using namespace std;class Complex{public:    Complex( )    {        real=0;        imag=0;    }    Complex(double r,double i)    {        real=r;        imag=i;    }    Complex & operator += (const Complex & c);    void display( );private:    double real;    double imag;};Complex & Complex::operator += (const Complex & c){    real += c.real;    imag += c.imag;    return *this;}void Complex::display( ){    cout<<"("<<real<<","<<imag<<"i)"<<endl;} int main( ){    Complex c1(3,4),c2(5,-10);    c1+=c2;    cout<<"c1=";    c1.display();    return 0;}