Is it possible to refactor this C# if(..) statement?

Question

simple question :-

i have the following simple if (..) statements :-

if (foo == Animal.Cat || foo == Animal.Dog)
{ .. }

if (baa == 1|| baa == 69)
{ .. }

is it possible to refactor these into something like ...

DISCLAIMER: I know this doesn't compile .. but this is sorta what i'm trying to get...

if (foo == (Animal.Cat || Animal.Dog))
{ .. }

if (baa == (1 || 69))
{ .. }

Cheers :)

EDIT

I wonder if a lambda expression extension could do this? :P

Answer 1

I usually create an extension method called IsIn() that takes a generic parameter array of type <T> and then calls .Contains() on it, passing the instance on which the extension is called.

It looks like if (foo.IsIn(foo1, foo2)). Very simple to write, super easy to use.

Answer 2

It's not much use in this specific case where you only have two options, but if there could be many options you might prefer to put the options in a list and then use Contains like this:

List<Animal> allowedAnimals = new List<Animal>
{
    Animal.Cat,
    Animal.Dog,
    Animal.Fish,
    Animal.Frog,
    Animal.Horse
};

if (allowedAnimals.Contains(animal))
{
    // etc...
}

This method will also work on other types than enums including types that you cannot switch on. It is also useful if the list of allowed values will only be known at runtime.

Note that if you create a new list each time there will be a performance penalty.