#399 – Overloading Unary Operators

You can overload any of the following unary operators: +, -, !, ~, ++, –, true, false.  A unary operator is an operator that can be applied to a single operand.

Overloading the negation (!) operator allows us to negate an instance of a class.

            Dog kirby = new Dog("Kirby", 13);

            Dog antiKirby = !kirby;

To overload the operator, we define a new method in our class that takes an instance of a Dog and “negates” it, returning a new instance.

        public static Dog operator !(Dog d1)
        {
            string notName = new string(d1.Name.Reverse().ToArray());

            return new Dog(notName, -1 * d1.Age);
        }

Below is an example of overloading the increment (++) operator.  (We really ought to overload the decrement operator as well).

            Dog olderKirby = kirby++;
        public static Dog operator ++(Dog d1)
        {
            return new Dog(d1.Name, d1.Age++);
        }

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About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

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