IEnumerable as return type

Question

Is there a problem with using IEnumerable as a return type? FxCop complains about returning List (it advises returning Coll

Answer 1

No, IEnumerable is a good thing to return here, since all you are promising is "a sequence of (typed) values". Ideal for LINQ etc, and perfectly usable.

The caller can easily put this data into a list (or whatever) - especially with LINQ (ToList, ToArray, etc).

This approach allows you to lazily spool back values, rather than having to buffer all the data. Definitely a goodie. I wrote-up another useful IEnumerable trick the other day, too.