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Is List<object> fundametally the same as ArrayList or should I prefer one over the other?
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Man, you're about as popular with the 1-voters as John the Outlaw Programmer is.  Are you running for his office??
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Dave Kreskowiak wrote: Are you running for his office??
No, but perhaps I should care what some loser that doesn't even know what generics is and can't be bothered to read documentation to learn about it, thinks about my post? Nah, not so much. 
led mike
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The first, is a generic list specifically of type object. the second is a non generic list, written to hold object types.
If you use "object" in the generic one, then yes they are pretty similar. but why are you storing a list of objects? You should create you list with the specific type you want to store
i.e. List<String>
Doing this is wayyyy better than using an ArrayList to hold strings because the generic form enforces type safety, you don't have to cast, and you don't have to write a specific class. (And in the case of value types, prevents boxing)
You can do some reading on generics here:
Intro to C# generics[^]
Generics - C# programming guide[^]
Simon
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I cannot tell the type of the data being collected at compile time. It could change based on the situation.
Brent
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dbrenth wrote: I cannot tell the type of the data being collected at compile time.
Then use an ArrayList!
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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if you're working with pure objects only then I don't think there's a great deal of difference. If not, the generic list is obviuosly far more flexible and much quicker as you can use any type without boxing/unboxing.
As there is no advantage to the ArrayList I never use them. This page[^] (is probably quite old) has a comparison of the two.
DaveBTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
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For the most part the way you interact with a List<T> and an ArrayList are the same. They provide very similar functionality to the calling code.
Specifically, List<Object> is defining a generic list of type Object so from a data type point of view it is the same as ArrayList since ArrayList can only contain objects.
In general, I think it is preferable to use the generics, particularly if you are working with strong data types (things other than objects) as you are able to get better performance from the generics because you no longer have most (if not all) of the boxing/unboxing operations that need to be performed. That being said, by creating a List<Object>, you probably aren't really gaining a whole lot over an ArrayList.
Scott Dorman Microsoft® MVP - Visual C# | MCPD
President - Tampa Bay IASA
[ Blog][ Articles][ Forum Guidelines]
Hey, hey, hey. Don't be mean. We don't have to be mean because, remember, no matter where you go, there you are. - Buckaroo Banzai
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List<object> and ArrayList are very similar, but there are some implementation differences:
The List<object> methods are not virtual and the List enumerator is a value type, whereas ArrayList requires virtual method calls and needs a heap allocation for the enumerator. So List<object> is a tiny bit faster than ArrayList.
I'd always use List<T>, even if you don't avoid any boxing and don't get any type safety in the List<object> case.
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If you're not able to appreciate the difference, use the ArrayList. The other way passes through led mike's suggestion.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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The generic List class has practically replaced the ArrayList class. Don't use the ArrayList class any more.
For the rare case where you actually need a list of object references, use List<object> instead of ArrayList. That way it's obvious that you needed exactly that kind of list, and that you are not just using ArrayList because you don't know any better.
Despite everything, the person most likely to be fooling you next is yourself.
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I am trying to create a table in an Access database
I have verified all of my SQL commands work in SQL Server so I'm figuring that i have a formatting for C# issue i am over looking or doing something wrong via the OLDDB driver
here is my code
String connect = "Provider=Microsoft.JET.OLEDB.4.0;data source=.\\Test.mdb";
OleDbConnection con = new OleDbConnection(connect);
con.Open();
OleDbCommand cmd = con.CreateCommand();
cmd.CommandText = "Create Table GroupPolicy(GUID char(50) NOT NULL Unique, GPONAME char(50), Domain Char(50), Created datetime, Modified datetime, Status char(10))";
try
{
cmd.ExecuteNonQuery();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
con.Close();
the exception is telling me there is a syntax error
Thanks
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Planker wrote: I am trying to create a table in an Access database
I have verified all of my SQL commands work in SQL Server
Access SQL is NOT EQUAL to SQL Server.
Therefore your test is invalid. Try testing your SQL in the Database you are targeting. That is always the best approach.
Good luck
led mike
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Thanks, I am trying to figure out what the correct commands are, I see examples all over the internet using the SQL create table command on a Access using OLEDB, but everything i try does not work.
modified on Wednesday, October 8, 2008 2:02 PM
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Planker wrote: Thanks, I am trying to figure out what the correct commands are
Sure, but wouldn't something like the documentation[^] be a good place to start?
led mike
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Thanks for pointing me in the right direction, I am making some progress now.
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Planker wrote: I am making some progress now.
Cool ![Beer | [beer]](https://www.codeproject.com/script/Forums/Images/beer.gif)
led mike
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Hi!
I am currently working on a project, where I have to make an API assembly to our main functionality.
The issue is that i'm in fact making two assemblies one, which is comon and one which intented as the assembly, which should expose the API functions to our customers. If I try to use the API assembly my common assembly is also required for the client program which is using my API assembly in order to compile, even though I have no direct referances to the common assembly are thiere any way that I can get around this so that I do not have to referance the common assembly in by client program ?
Many thanks in advance.
Kind regards
Jakob
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Ummmm, what?
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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Well I will try to clarify. I have two assemblies, which makes up my api and I will like to keep that way and I only want to expose one of the assemblies to my custormers. So that they in principle only have worry about one of the assemblies and referance only one assembly in there client programs.
I hope this clarifies the problem.
Kind regards
Jakob
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If there are no dependencies between them why not just compile them as two independant dll's?
If there are interdependencies then just compile them to a single dll.
Or have I missed the point entirely?
Bob
Ashfield Consultants Ltd
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Instead of doing two assemblies, make one, and make the classes in the non-public one private within the public one.
Any public object in an assembly will be exposed. See if there's an .Net attribute available that marks a class as not exposed or something like that. If not, you'll have to follow my first suggestion.
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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Yes you can. Although I would not recommend it you can embed the assembly as a resource in another assembly and then return it from an Assembly Resolve event such as
appDomain.AssemblyResolve += new ResolveEventHandler(OnAssemblyResolve);
In the event call your assembly and ask for the other assembly as a binary file and viola.
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Most of this sig is for Google, not ego.
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No, but you can have a class inside a class, is that what you mean?
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