LINQ: select keys with given value

Question

I have Dictionary<int key, int sum>. I need select all keys where sum==1.

How I could do it with LINQ ?

Dmitry Bychenko · Accepted Answer · 2017-07-18T10:23:26.333

5

Put Where to filter out key-value pairs by values and Select to narrow down key-value pairs to keys:

 var keys = myDictionary
   .Where(pair => pair.Value == 1)
   .Select(pair => pair.Key)
   .ToArray(); // if you want an array of these keys

edited Jul 18 '17 at 10:23

answered Jul 18 '17 at 10:13

Dmitry Bychenko

Ok, i get IEnumerate object. How to get integer from keys ? – Mateusz Szymański Jul 18 '17 at 10:21
1

@Mateusz Szymański: Well, you wanted "select all keys where `sum==1`" and my code enumerates them; you can add *materialization*, say, `ToArray()` - see my edit - if you want an array of such keys – Dmitry Bychenko Jul 18 '17 at 10:25
All is ok. Thanks :) – Mateusz Szymański Jul 18 '17 at 10:29

1 Answers1