Accessing Arraylist Collection

[Guest]

Hi,

I have created an Arraylist object from an Arraylist class.
I added rows to the arraylist object and I need to find a particular record
in my arraylist. How do I do this? Also if I was in the middle of building
the arraylist and wanted to call the last record added to arraylist object
how can I do this?

Thanks,

JJ

 

[Jon Skeet [C# MVP]]

I have created an Arraylist object from an Arraylist class.
I added rows to the arraylist object and I need to find a particular record
in my arraylist. How do I do this?

Do you mean by row number, or by row object? If it's by row object, use
IndexOf. If it's by row number, use the indexer:

object o = arrayList[rowNumber];

Also if I was in the middle of building the arraylist and wanted to
call the last record added to arraylist object how can I do this?

Use the indexer again, along with the Count property:

object last = arrayList[arrayList.Count-1];

 

[Guest]

ok so how would I update a record in an arrowlist? So how would I be able to
check or get individual items of arraylist?

Thanks,

JJ

I have created an Arraylist object from an Arraylist class.
I added rows to the arraylist object and I need to find a particular record
in my arraylist. How do I do this?

Do you mean by row number, or by row object? If it's by row object, use
IndexOf. If it's by row number, use the indexer:

object o = arrayList[rowNumber];

Also if I was in the middle of building the arraylist and wanted to
call the last record added to arraylist object how can I do this?

Use the indexer again, along with the Count property:

object last = arrayList[arrayList.Count-1];

 

[Bob Grommes]

JJ,

It works pretty much like an array of objects except that the number of
elements is dynamic rather than fixed. To update:

arrayList[rowNumber] = newThing;

To extract an item:

object oldThing = arrayList[rowNumber];

I'm leaving out casting; if the items in the arraylist are of a particular
type, say MyType:

MyType oldThing = (MyType)arrayList[rowNumber];

You should Google and read one of the basic tutorials and/or check out the
help for ArrayList -- particularly the Add(), AddRange(), IndexOf(),
Remove() and RemoveAt() methods, the Count property and of course the Item
property (indexer in C#) which I've focused on above.

--Bob

ok so how would I update a record in an arrowlist? So how would I be able
to
check or get individual items of arraylist?

Thanks,

JJ

I have created an Arraylist object from an Arraylist class.
I added rows to the arraylist object and I need to find a particular
record
in my arraylist. How do I do this?

Do you mean by row number, or by row object? If it's by row object, use
IndexOf. If it's by row number, use the indexer:

object o = arrayList[rowNumber];

Also if I was in the middle of building the arraylist and wanted to
call the last record added to arraylist object how can I do this?

Use the indexer again, along with the Count property:

object last = arrayList[arrayList.Count-1];