#400 – Overloading Binary Operators

You can overload any of the following binary operators: +, -, *, /, %, &, |, ^, <<, >>.  A binary operator is an operator applied to two operands.

For example, assume we have a Dog class that has the following bool properties: BarksALot, LikesBalls and Sheds.  We might implement the & operator for the Dog class so that we get a new Dog instance with all of the boolean properties AND’d together.

        public static Dog operator &(Dog d1, Dog d2)
        {
            Dog newDog = new Dog(string.Format("{0} & {1}", d1.Name, d2.Name), 0);

            newDog.BarksALot = d1.BarksALot & d2.BarksALot;
            newDog.LikesBalls = d1.LikesBalls & d2.LikesBalls;
            newDog.Sheds = d1.Sheds & d2.Sheds;

            return newDog;
        }

We can now apply this operator to two Dog instances.

            Dog kirby = new Dog("Kirby", 13);
            kirby.LikesBalls = true;
            kirby.BarksALot = true;

            Dog jack = new Dog("Jack", 10);
            jack.Sheds = true;
            jack.BarksALot = true;

            Dog newguy = kirby & jack;