Check if a variable is in an ad-hoc list of values

Question

Is there a shorter way of writing something like this:

if(x==1 || x==2 || x==3) // do something

Wha

Answer 1

If it's in an IEnumerable, use this:

if (enumerable.Any(n => n == value)) //whatever

Else, here's a short extension method:

public static bool In(this T value, params T[] input)
{
    return input.Any(n => object.Equals(n, value));
} 

Put it in a static class, and you can use it like this:

if (x.In(1,2,3)) //whatever