c++ 双目运算符重载

双目运算符重载

在使用被重载的运算符时，系统就自动调用该函数，运算符的重载实质上就是函数的重载。

（1）复数与复数相加

#include <iostream>

using namespace std;

class complex

{

public:

    complex(){real=0,imag=0;}

    complex(double r,double i):real(r),imag(i){}

    friend complex operator +(complex c1,complex c2);     //重载函数作为友元函数

    void display();

private:

    double real,imag;

};

complex operator +(complex c1,complex c2)

{

    complex c;

    c.real=c2.real+c1.real;

    c.imag=c2.imag+c1.imag;

    return c;

}

void complex::display()

{

    cout<<"("<<real<<","<<imag<<")"<<endl;

}

int main()

{

    complex c1(1,3),c2(2,4),c3;

    c3=c2+c1;

    c3.display();

    return 0;

}

（2）复数与实数相加，输出复数，将实数转化为类对象，用到转换构造函数。

#include <iostream>

using namespace std;

class complex

{

public:

    complex(){real=0,imag=0;}

    complex(double r,double i):real(r),imag(i){}

    complex(double r){real=r,imag=0;}                    //将实数转化为复数

    friend complex operator +(complex c1,complex c2);  //重载函数作为友元函数

    void display();

private:

    double real,imag;

};

complex operator +(complex c1,complex c2)

{

    complex c;

    c.real=c2.real+c1.real;

    c.imag=c2.imag+c1.imag;

    return c;

}

void complex::display()

{

    cout<<"("<<real<<","<<imag<<")"<<endl;

}

int main()

{

    complex c1(1,3),c3;

    c3=1.5+c1;

    c3.display();

    c3=c1+1.5;

    c3.display();

    return 0;

}

（3）复数与实数相加，输出实部，用到类型转换函数，将类对象转化为实数

#include <iostream>

using namespace std;

class complex

{

public:

    complex(){real=0,imag=0;}

    complex(double r,double i):real(r),imag(i){}

    operator double(){return real;}

    void display();

private:

    double real,imag;

};

int main()

{

    complex c1(1,3);

    double d;

    d=1.5+c1;

    cout<<"d="<<d<<endl;

    return 0;

}

有的地方不是写的很详细，希望能为刚接触c++的初学者提供小小的帮助，同时也希望大佬多多指出不足，我会加以修改。