Get the element from hashset where hashset.Count==1

Question

How to get the element from hashset that is known to contain exactly 1 element? (without iterating it)

juergen d · Accepted Answer · 2022-02-08T07:36:08.780

20

You could use Single()

var element = yourHashSet.Single();

edited Feb 08 '22 at 07:36

answered Aug 03 '12 at 09:33

juergen d

2

But it is (a form of) iterating. – Henk Holterman Aug 03 '12 at 10:17
5

And requires LINQ that answer should suggest. – Feri Aug 27 '19 at 21:39
1

Ref. [this answer](https://stackoverflow.com/questions/2724096/linq-single-vs-first#answer-2724246) to whether `.First()` or `.Single()` should be used, I'd suggest using `.Single()` rather than `.First()` -- seeing as getting the knowingly only item in the hash set is the intent here. – Astrid E. Feb 08 '22 at 07:32

score -1 · Answer 2 · answered Feb 08 '22 at 04:38

I had a HashSet<object> that for some reason couldn't be accessed with [0] or .First().

Though technically iterating, I'm leaving this here just in case someone else with my issue runs into this post.

foreach (var i in myHash){
    object o = i;
    break;
}

Simply start to iterate, then immediately break the iteration.

2 Answers2