Matt,
I'll assume you have NOT read the MSDN documentation on Array, ArrayList and
a Collection. Which you should!
As for when to use which, it is more of a style or speed issue.
Something to keep in mind is that a collection is nothing more than array
that has a whole lot of code wrapped around it to manage adding/expanding
the array. This is why speed can be an issue.
Now since most applications need to be more maintainable than fast, I try to
use the following guide lines when deciding which to use.
If you know the number of objects to be stored use an array. If not, use a
collection.
If after creating an array a process must add an unknown number of objects
to it use a collection.
In my experiance designing reusable objects, It is not a good practice to
allow objects to return/expose Arrays or ArrayLists. This is because it
never fails that I have to end up and add code to all my methods to make
sure that each list object is the type that I'm expecting. What I do is to
create a class that inherats from CollectionBase so that only objects of
expected types are allowed to be added. By doing this it forces a "Strong
Typed" structure, which is the been found to be the easiest to
code(opinion).
Hope this helps.
