Passing and Returning Objects 2

[LenardD]

Take the following code:

protected DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, DataSet dataSet, string tableName )
{
// fill code
.....

return dataSet;
}

When the "dataSet" object is returned, what exactly gets returned.....a copy of the dataSet object or the reference to the dataSet object that was passed via the method?

Thanks.

 

[Craig0201]

The dataset. Functions return values, not references.

Craig

 

[LenardD]

Thanks Craig. That is what I thought.

I don't know why one would want to code a method this way when one has a reference to the object to begin with. If you are dealing with a large dataset object, it's not very efficient.

Just some code I found in a book and thought "maybe I was missing something".

--Lenard

 

[Craig0201]

Lenard,

No, it's not efficient but remember that the original will get garbage collected as it will have gone out of scope.

It may be that something does happen under the covers that does pass a reference but I doubt it. For example, I may be returning the dataset to a client from the server directly.

Craig

 

[chiph]

Ummm, pretty sure it returns a reference, as a DataSet is a reference type (i.e. a class), not a value type (a struct). It's declared as:

public class DataSet : MarshalByValueComponent, IListSource, ISupportInitialize, ISerializable

Chip H.

 

[LenardD]

Hmmm, OK. I think I will email the original author and see if he can confirm. I will let you know what he says.

Thanks Chip.

--Lenard

 

[LenardD]

Chip,

You are right, you get back the original dataset.

Thanks for replying to my post.

--Lenard