C# OPERATOR OVERLOADING

You can redefine or overload most of the built-in operators available in C#. Thus a programmer can use operators with user-defined types as well. Overloaded operators are functions with special names the keyword operator followed by the symbol for the operator being defined. Similar to any other function, an overloaded operator has a return type and a parameter list

using System;

namespace ConsoleApp1
{
    class Box
    {
        private double length; // Length of a box
        private double breadth; // Breadth of a box
        private double height; // Height of a box
        public double getVolume()
        {
            return length * breadth * height;
        }
        public void setLength(double len)
        {
            length = len;
        }
        public void setBreadth(double bre)
        {
            breadth = bre;
        }
        public void setHeight(double hei)
        {
            height = hei;
        }
        // Overload + operator to add two Box objects.
        public static Box operator +(Box b, Box c)
        {
            Box box = new Box();
            box.length = b.length + c.length;
            box.breadth = b.breadth + c.breadth;
            box.height = b.height + c.height;
            return box;
        }
    }
    class Tester
    {
        static void Main(string[] args)
        {
            Box Box1 = new Box(); // Declare Box1 of type Box
            Box Box2 = new Box(); // Declare Box2 of type Box
            Box Box3 = new Box(); // Declare Box3 of type Box
            double volume = 0.0; // Store the volume of a box here
                                 // box 1 specification
            Box1.setLength(6.0);
            Box1.setBreadth(7.0);
            Box1.setHeight(5.0);
            // box 2 specification
            Box2.setLength(12.0);
            Box2.setBreadth(13.0);
            Box2.setHeight(10.0);
            // volume of box 1
            volume = Box1.getVolume();
            Console.WriteLine("Volume of Box1 : {0}", volume);
            // volume of box 2
            volume = Box2.getVolume();
            Console.WriteLine("Volume of Box2 : {0}", volume);
            // Add two object as follows:
            Box3 = Box1 + Box2;
            // volume of box 3
            volume = Box3.getVolume();
            Console.WriteLine("Volume of Box3 : {0}", volume);
            Console.ReadKey();

            //Volume of Box1: 210
            //Volume of Box2: 1560
            //Volume of Box3: 5400
        }
    }
}