It means that HashSet does not maintains the order of its elements. Hence sorting of HashSet is not possible. However, the elements of the HashSet can be sorted indirectly by converting into List or TreeSet, but this will keep the elements in the target type instead of HashSet type.

Is HashSet ordered or unordered?

Ordering : ArrayList maintains the order of the object in which they are inserted while HashSet is an unordered collection and doesn’t maintain any order.

Is HashSet ordered in C#?

4 Answers. Standard . NET HashSet do not preserve the insertion order. For simple tests the insertion order may be preserved due to an accident, but it’s not guaranteed and would not always work that way.