does an list of lists smell bad, what are my other options

Question

I need to assemble an list of lists, but the whole idea doesn't sound too pretty. It just sounds so cumbersome. is there some other pattern for holding a list of lists.

my first though is to use an arrayList of Arraylist.

c#, .net-2

more: then number of items to be stored is small but always changing.

NOTE: I was corrected on the use of ArrayLists on this Question:

What's wrong with using an ArrayList in .net-2.0

Answer 1

There's nothing wrong with List<List<T>> - LINQ's SelectMany can be your friend in that situation.

Answer 2

Not a problem at all. I've already used it and it was a fit for what I needed at the time. The pattern is a list of lists. :)

Answer 3

A list of lists is not, of itself, a bad smell. If your lists are all going to be of the same size, you may want to use a 2D array e.g. int[2,2], but if the lists are of different lengths, then a list of lists is the right way to go, short of formally coding a class for a ragged 2D array.

Answer 4

How about using objects created in custom classes?

For example, Customers can have multiple Addresses. Create a Customer object which has an Address property. Then, you can have a collection (array, ArrayList, etc) of Customers, and each Customer can have a collection of Addresses.

This fits many kinds of information, such as Products in Product Categories, Employees in Departments.

It's easier in coding to handle the hierarchical relationship this way.

Answer 5

you can but it'd better to wrap it to a class with well defined public methods.

Answer 6

You can certainly do that either using generic lists or the non-generic variant, ArrayList.

List<List<string>> listOfLists = new List<List<string>>();
listOfLists.Add(new List<string>());
listOfLists.Add(new List<string>());

ArrayList stringListOfStringLists = new ArrayList();
stringListOfStringLists.Add(new ArrayList());
stringListOfStringLists.Add(new ArrayList());