I noticed in my code, which is essentially an api for the client, that
I return ArrayList object to the client. In my case, list consist of
some objects that user only need to iterate over, hence no
modification to list is done after it filled by me.

What do you think is the best data structure for this requirement?

Thanks

On Oct 16, 11:05 am, puzzlecracker <ironsel2...@gmail.com> wrote:
> I noticed in my code, which is essentially an api for the client, that
> I return ArrayList object to the client. In my case, list consist of
> some objects that user only need to iterate over, hence no
> modification to list is done after it filled by me.
>
> What do you think is the best data structure for this requirement?
>
> Thanks

You should return a readonly collection. Take a look at
ReadOnlyCollection , it's in System.Collections.ObjectModel

On Oct 16, 11:27*am, "Ignacio Machin ( .NET/ C# MVP )"
<ignacio.mac...@gmail.com> wrote:
> On Oct 16, 11:05 am, puzzlecracker <ironsel2...@gmail.com> wrote:
>
> > I noticed in my code, which is essentially an api for the client, that
> > I return ArrayList object to the client. In my case, list consist of
> > some objects that user only need to iterate over, hence no
> > modification to list is done after it filled by me.
>
> > What do you think is the best data structure for this requirement?
>
> > Thanks
>
> You should return a readonly collection. Take a look at
> ReadOnlyCollection , it's in System.Collections.ObjectModel

I think it is part of 3.0+, I need to support .NET 2.0... suggestions?

"puzzlecracker" <(E-Mail Removed)> wrote in message
news:3815ca86-54a8-4039-b6b1-(E-Mail Removed)...
> On Oct 16, 11:27 am, "Ignacio Machin ( .NET/ C# MVP )"
> <ignacio.mac...@gmail.com> wrote:
>> On Oct 16, 11:05 am, puzzlecracker <ironsel2...@gmail.com> wrote:
>>
>> > I noticed in my code, which is essentially an api for the client, that
>> > I return ArrayList object to the client. In my case, list consist of
>> > some objects that user only need to iterate over, hence no
>> > modification to list is done after it filled by me.
>>
>> > What do you think is the best data structure for this requirement?
>>
>> > Thanks
>>
>> You should return a readonly collection. Take a look at
>> ReadOnlyCollection , it's in System.Collections.ObjectModel
>
> I think it is part of 3.0+, I need to support .NET 2.0... suggestions?

Why not use an ArrayList internally and then convert the ArrayList to an
array and return that?

Kip

On Oct 16, 5:04*pm, puzzlecracker <ironsel2...@gmail.com> wrote:
> > You should return a readonly collection. Take a look at
> > ReadOnlyCollection , it's in System.Collections.ObjectModel
>
> I think it is part of 3.0+, I need to support .NET 2.0... suggestions?

What makes you think that? From MSDN:
http://msdn.microsoft.com/en-us/library/ms132474.aspx

<quote>
Version Information
..NET Framework
Supported in: 3.5, 3.0, 2.0
</quote>

Jon

On Oct 16, 12:41*pm, "Jon Skeet [C# MVP]" <sk...@pobox.com> wrote:
> On Oct 16, 5:04*pm, puzzlecracker <ironsel2...@gmail.com> wrote:
>
> > > You should return a readonly collection. Take a look at
> > > ReadOnlyCollection , it's in System.Collections.ObjectModel
>
> > I think it is part of 3.0+, I need to support .NET 2.0... suggestions?
>
> What makes you think that? From MSDN:http://msdn.microsoft.com/en-us/library/ms132474.aspx
>
> <quote>
> Version Information
> .NET Framework
> Supported in: 3.5, 3.0, 2.0
> </quote>
>
> Jon

I was wrong, it's supported... I first encountered it in the book
on .Net 3.0, hence the erroneous assumption.

Mythran wrote:

> Why not use an ArrayList internally and then convert the ArrayList to
> an array and return that?

Perhaps because "converting the ArrayList to an array" would mean
copying data from the ArrayList to the array, perhaps even multiple
times, and that is relatively slow, if compared to giving people direct
(but readonly) access.

--
Rudy Velthuis http://rvelthuis.de

"We totally deny the allegations, and we are trying to identify
the allegators."

On Oct 16, 2:22*pm, "Rudy Velthuis" <newsgro...@rvelthuis.de> wrote:
> Mythran wrote:
> > Why not use an ArrayList internally and then convert the ArrayList to
> > an array and return that?
>
> Perhaps because "converting the ArrayList to an array" would mean
> copying data from the ArrayList to the array, perhaps even multiple
> times, and that is relatively slow, if compared to giving people direct
> (but readonly) access.
>
> --
> Rudy Velthuis * * * *http://rvelthuis.de
>
> "We totally deny the allegations, and we are trying to identify
> *the allegators."

Does arraylist uses a traditional array and List uses nodes to store
elements, much like in Java?

puzzlecracker wrote:

> Does arraylist uses a traditional array and List uses nodes to store
> elements, much like in Java?

No, List<T> is simply the generic equivalent of ArrayList. Both
internally use an array to hold the list elements. But ArrayList uses
an array of objects, while List<T> uses an array of instances of type T.

--
Rudy Velthuis http://rvelthuis.de

"Barabási's Law of Programming: Program development ends when the
program does what you expect it to do — whether it is correct or
not." -- Albert-László Barabási

Peter Duniho wrote:

> On Thu, 16 Oct 2008 11:41:42 -0700, puzzlecracker
> <(E-Mail Removed)> wrote:
>
> > Does arraylist uses a traditional array and List uses nodes to
> > store elements, much like in Java?
>
> ArrayList, List<T>, and Java's ArrayList all use arrays to store
> elements.

Quite right, but I guess he meant that Java's List class is in fact
implemented as a doubly linked list.

--
Rudy Velthuis http://rvelthuis.de

"No Sane man will dance." -- Cicero (106-43 B.C.)