Question

If I have an IEnumerable object in my .net code that contains a single element, what is the best way to convert the IEnumerable to a single object while checking that the IEnumerable does, indeed, contain only one element?

Here are a couple of ideas that come to mind:

IEnumerable<string> strings = getStrings();
if (string.Count() != 0 ) throw new Exception();
else return strings.First();

return getStrings().Single(x => true);

Answer 1

If your goal is to raise an exception anyways, you can just use:

return getStrings().Single();

This will automatically raise an InvalidOperationException if there is more than one string in the enumeration.