Reputation: 2368
Is Dictionary the best way to record presence or absence of a key
Apologies if this has already been asked elsewhere, but I couldn't find it.
I want to store a set of strings in .NET, in such as way that they can be easily and quickly looked up to find if the key is stored or not.
I could just use a List<string> and enumerate the list every time I need to search, but obviously that linear search is quite inefficient.
So my next thought is to use a Dictionary<string, object> and query that each time, which should hopefully result in some cool string hashing and faster search times. However, I'm not actually storing anything in the "object" part of the dictionary so it seems like there might be an inefficiency there.
Is there any better way to do this?
Upvotes: 3
Views: 182
Answers (3)
Reputation: 1981
If your dictionary object is being used by multiple threads, ConcurrentDictionary(Of TKey, TValue) is be a better choice.
Upvotes: 0
Reputation: 4371
HashSet<string> for unordered sets or
SortedSet<string> if order is importent.
Upvotes: 2
Reputation: 887957
You're looking for a HashSet<string>, which provides the same O(1) performance of a dictionary, but without those pesky values.
Upvotes: 10
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