Append Items to Collection: Value cannot be null. (Parameter 'Collection')

Help Studio
, ,
1

Hi,

I am getting the above issue when appending the new value to the collection.

Capture
Capture1920×1080 184 KB

ALso how do we display the Collection in message box.

Thanks

2

@darshan93shastri,

Make sure your collection variable is initialized before you append any items to it and it’s not null.

Thanks,
Ashok :slight_smile:

3

Hi @darshan93shastri

Can you try the below

The image depicts a visual workflow sequence in a development environment that collects a user input, creates a list, appends the input to the list in a loop, increments a counter, and finally displays the list in a message box. (Captioned by AI)
The image depicts a visual workflow sequence in a development environment that collects a user input, creates a list, appends the input to the list in a loop, increments a counter, and finally displays the list in a message box. (Captioned by AI)818×1181 53.6 KB

This image shows a list of variables in a software interface, detailing their names, variable types, scopes, and default values. (Captioned by AI)
This image shows a list of variables in a software interface, detailing their names, variable types, scopes, and default values. (Captioned by AI)1078×332 13.9 KB

String.Join(", ",TicketContainer)

Sequence15.xaml (15.5 KB)

Regards,

4

From above screenshot we cannot derive all details and the overall goal. Especially the information on what is added to the list is missing.

In case that the same item is added multiple times to the list we can do it within a single assign actvitiy

grafik

myList =Enumerable.Repeat(myStringVar,UserInputVarAsInt32).ToList()

5

Hi @darshan93shastri,

It is throwing the error because the variable is not initialized.

In the variables pane, change the Variable Type to List<string> and Default to New List(of String).

Regards,
Ranjith Udayakumar

6

Thank you @lrtetala @ashokkarale @ppr @ranjith_udayakumar all these responses have been helpful…

1 Like