Question

I’m trying to find the most reusable, yet elegant, piece of code possible for determining if an IEnumerable. In the ideal, this should be a function I can call absolutely any time I need to tell if an IEnumerable is empty.

While I have developed an answer for .NET 3.5 that has worked well for me so far, my current thought is that there is no perfect answer, since an IEnumerable can technically encapsulate a collection (or queue of iterators) that modifies the underlying results as it iterates, which would cause problems. However, this would also be an impediment to implementing IEnumerable.Count(), and that didn’t stop MS from providing it.

So I thought I’d put it to SO to see if someone has a better one, and in case someone else should find it useful.

Edit: Wow, I can’t believe I didn’t know about IEnumerable.Any. I knew it existed, but never bothered to check what it did. Let this be a lesson. Read the documentation. Just because a method name doesn’t imply it does what you want, doesn’t mean it doesn’t do what you want.

Answer 1

!enumerable.Any() 

Will attempt to grab the first element only.

To expand on how/why this works, any determines if any of the components of an IEnumerable match a given function, if none is given, then any component will succeed, meaning the function will return true if an element exists in the enumerable.