运算符重载-蒲公英云

运算符重载

运算符重载函数作为成员函数

class Complex {
public:
    Complex() { 
        real = 0.0, imag = 0.0;
    }
    Complex(double real, double imag) {
        this->real = real;
        this->imag = imag;
    }
    Complex operator+ (Complex &c2);
    void display();
private:
    double real,imag;
};
//运算符重载函数定义：
Complex Complex::operator+(Complex &c2) {
    Complex c;
    c.real = real + c2.real;
    c.imag = imag + c2.imag;
    return c;
    //return(Complex(real+c2.real,imag+c2.imag)）;//这样比较简便
}
void Complex::display() {
    cout << real << "+" << imag << "i" << endl;
}
int main() {    
    Complex c1(3, 1);
    Complex c2(4, 4);
    Complex c = c1 + c2;
    c.display();
    system("pause");        
}

解读

1 运算符的重载实质上函数的重载。
c1 + c2相当于c1.operator+(c2)，这里operator+是一个函数名。

不允许重载的运算符

成员访问运算符	成员指针访问运算符	域运算符	长度运算符	条件运算符
.	*	：：	sizeof	？：

运算符重载函数作为友元类函数（效果与上面相同）

class Complex {
public:
    Complex() { 
        real = 0.0, imag = 0.0;
    }
    Complex(double real, double imag) {
        this->real = real;
        this->imag = imag;
    }
    friend Complex operator+ (Complex &c1, Complex &c2);
    void display();
private:
    double real,imag;
};
void Complex::display() {
    cout << real << "+" << imag << "i" << endl;
}
Complex operator+ (Complex &c1, Complex &c2) {
    return Complex(c1.real + c2.real, c1.imag + c2.imag);
}
int main() {    
    Complex c1(3, 1);
    Complex c2(4, 4);
    Complex c = c1 + c2;
    c.display();
    system("pause");        
}