运算符重载（作为成员函数）

 1 #include<iostream>
 2 using namespace std;
 3 class Complex{
 4 private:
 5         double real;
 6         double    imaginary;
 7 public:
 8         Complex(double a=0.0,double b=0.0) : real(a),imaginary(b) {}//初始化 
 9         ~Complex(){}
10         Complex operator+(Complex& a);
11         Complex operator-(Complex& b);
12         void print();
13 };
14 Complex Complex::operator+(Complex& a){
15     return Complex(real+a.real,imaginary+a.imaginary);
16 }//运算符重载函数(作为成员函数) 
17 Complex Complex::operator-(Complex& a){
18     return Complex(real-a.real,imaginary-a.imaginary);
19 }//运算符重载函数(作为成员函数)
20 void Complex::print(){
21     cout<<real<<"+"<<imaginary<<"i"<<endl; 
22 }
23 int main()
24 {
25     Complex x,y(3,7),z(2,3);
26     x=y+z;//相当于y.operator+(z),z为参数 
27     x.print();
28     x=y-z;//相当于y.operator-(z),z为参数
29     x.print();
30     return 0;
31 }