Initial capacity of collection types, e.g. Dictionary, List

Question

Certain collection types in .Net have an optional \"Initial Capacity\" constructor parameter. For example:

Dictionary something = new          


        

Answer 1

If you know the size, then tell it; a minor optimisation in most "small" cases, but useful for bigger collections. I would mainly worry about this if I am throwing a "decent" amount of data in, as it can then avoid having to allocate, copy and collect multiple arrays.

Most collections indeed use a doubling strategy.