Linq with dot notation - which is better form or what's the difference between these two?

Question

I've been reading Jon Skeet's C# In Depth: Second Edition and I noticed something slightly different in one of his examples from something I do myself.

He has something similar to the following:

var item = someObject.Where(user => user.Id == Id).Single();

Whereas I've been doing the following:

var item = someObject.Single(user => user.Id == Id);

Is there any real difference between the two? I know Jon Skeet is pretty much the c# god so I tend to think his knowledge in this area is better than mine so I might be misunderstanding something here. Hope someone can help.

Answer 1

The queries should be equal when the tree is evaluated, however depending on the target the actual execution could differ (IE L2S optimization).

Answer 2

I typically think in terms of "filter then take a single value". On the other hand, when it comes to Count I'll often use the version with the predicate. For Any I can go either way pretty easily depending on my mood :)

Ultimately it's unlikely to make any significant difference - use whichever is easier to understand at the time. I certainly wasn't trying to avoid using the versions with predicates etc - and I give some examples using them on P499.

While there are some situations with "definitely more readable" versions, many other cases are pretty much equally readable either way.