一、格式

返回值型別 operator 運算子（形參表）
{
   . . . . . .
}

二、試例

#include<iostream>
using namespace std;
class Complex
{
    public :
        int real;
        int imag;
        Complex(int a=0,int b=0):real(a),imag(b) {}//建構函式
        Complex operator-(const Complex &c）//運算子過載
        {
            
 
return Complex(real-c.real,imag-c.imag);//呼叫類中的建構函式
        }
};
Complex operator+(const Complex &a,const Complex &b)//運算子過載
{
    return Complex(a.real+b.real,a.imag+b.imag);//原理：呼叫類中的建構函式 
}
int main()
{
    Complex a(4,4),b(1,1),c;
    c=a+b;
    cout<<"c="<<c.real<<"
 
 "<<c.imag<<endl;
    cout<<"a="<<a.real<<" "<<a.imag<<endl;
    a=a-b;
    cout<<"a="<<a.real<<" "<<a.imag<<endl;
    return 0;
}