vb.net Code:
'Create a collection object by invoking a constructor.
'The collection is initially empty, i.e. has a Count of 0.
Dim mb As New List(Of String)
'Add an item to the collection.
'The collection grows dynamically and now has a Count of 1.
mb.Add("xyz")
Note that collections generally use arrays internally but they manage them in a relatively efficient way that would require you to write a significant amount of code to replicate if you were to use arrays and "resize" them yourself. I use the quotes because you can't actually resize an array but must actually create a new array object of the desired size and copy the elements between the two. Much of that can be automated but it's still a pain to do efficiently.