How the Dictionary is internally maintained?

Question

When i say

Dictionary

is it equivalent to two different arrays such as:

int[] keys =new int[] { 1, 2, 3          


        

Answer 1

That's not too far off. Looking at the source code in Reflector, it seems three internal collections are used:

private Entry[] entries;
private KeyCollection keys;
private ValueCollection values;

Note that there is also a int[] buckets variable to keep track of the buckets required in the case of hash-code collisions.

These variables' purposes should all be fairly self-explanatory. This is not particularly surprising, anyway, since the Dictionary class is known and documented to provide (ideally, with one item per bucket) O(1) lookup time.