Operater Overloading

Operator overloading is a type of function name overloading. The syntax for defining operator overloading is similar to the definition of the member function. An ‘operator function’ is declared and defined. For this, the function name is replaced with the keyword ‘operator’ followed by the operator to be overloaded. The general form and syntax for operator overloading is :

return-type class-name:: operator op (argument-list)

{

body of the function

}

Where op is the operator to be overloaded. The function operator op() is called the operator function. The return-type refers to the data type returned by the operator function. The operator function can be declared as a member function or a friend function.

/* Simple example to demonstrate the working of operator overloading*/

#include <iostream>
class object
{
public:
    int a;
    int b;
    object operator+(const object& obj); //declaration of overloaded function
    void operator=(const object& obj);
};

void object::operator=(const object& obj)
{
    (*this).a = obj.a;
    (*this).b = obj.b;

    return;
}

object object::operator+(const object& obj2) //definition of overloaded function
{
    object tmp_obj = *this;
    tmp_obj.a = tmp_obj.a + obj2.a;
    tmp_obj.b = tmp_obj.b + obj2.b;
    return tmp_obj;
}

int main(void)
{
    object obj1, obj2, obj3;

    obj1.a = 1;
    obj1.b = 1;

    obj2.a = 2;
    obj2.b = 2;

    obj3.a = 0;
    obj3.b = 0;

    obj3 = obj1 + obj2;

    std::cout<<obj3.a<<"  "<<obj3.b<<"\n";

    return 0;
}

Output:

3  3