Browsing sample code I'm seeing a usage I don't understand:
var orderRow = order.Rows.Single();
Rows is an enumerable and usually one would iterate using a foreach loop. Is the .Single a workaround for cases where, for whatever reason, the foreach can't be (or need not) be used?
var option = options.OfType<AdditionalLocationsOption>().SingleOrDefault();
if (option != null){
...stuff
}
LINQ's Single method returns the single element in a collection.
This would be written in Rows is known to contain exactly one row.
If it's empty, or if it has more than one row, an exception will be thrown.