newbie question: A variable size vector in c#/NET

Question

Hi all,

I come from the C/C++ world.
To my surprise, I've discovered that there is no variable size vector with constant access time when you index Nth element.
There is a List<T>, as Generics, that should implement, as far as I've understood, a typical list data structure with insert/remove constant access time
but with linear access time when you index a particular element.

Have I right understood?

thanks

Answer 1

List<T> are implemented internally as arrays that are resized as required. So access is linear, but adding may require a reallocation and copy. So they are really vectors.

Dictionary<k,t> are implemented as hash tables.

The current version of C# also has Span<T> which is stack allocated memory buffer.