How to Overload the (+) Plus Operator in C++?

In C++, operator overloading is a feature of the OOPs concept that allows you to redefine the behavior for different operators when they are used with objects of user-defined classes. The plus operator (+) is a binary operator generally used for addition. In this article, we will learn how to overload the (+) plus operator in C++ for a user-defined class.

Overloading the Plus(+) Operator in C++

To overload the plus operator, we have to create an operator+ function inside our class and define its behavior inside this function's body. The following syntax shows how to do it:

myClass operator+ (const myClass& obj) const {
     // new behaviour
}

C++ Program to Overload the Plus(+) Operator for a Class

// C++ program to demonstrate operator overloading of plus
// operator
#include <iostream>
using namespace std;

// Class definition
class MyClass {
private:
    int value;

public:
    // Constructors
    MyClass(): value(0){}
  
    MyClass(int val): value(val){}

    // Overloaded operator +
    MyClass operator+(const MyClass& other) const
    {
        MyClass result;
        result.value = this->value + other.value;
        return result;
    }

    // Getter method
    int getValue() const { return value; }
};

int main()
{
    // Create objects
    MyClass obj1(5);
    MyClass obj2(10);

    // Use overloaded operator +
    MyClass result = obj1 + obj2;

    // Output result
    cout << "Result: " << result.getValue() << endl;

    return 0;
}

Result: 15

To know more about operator overloading, refer to the article - Operator Overloading in C++