How is the c#/.net 3.5 dictionary implemented?

Question

I\'m using an application which uses a number of large dictionaries ( up to 10^6 elements), the size of which is unknown in advance, (though I can guess in some cases). I\'m

Answer 1

MSDN says: "Retrieving a value by using its key is very fast, close to O(1), because the Dictionary class is implemented as a hash table." and further on "the capacity is automatically increased as required by reallocating the internal array."

But you get less reallocations if you give an initial estimate. If you have all items from the beginning the LINQ method ToDictionary might be handy.