I have a list of event records that I am  de-duplicating. Each record contains a title, a date, and an alphanumeric ID (needed for an external function).  I wish to deduplicate records based on the combo of Title and Date only, because the ID will always be unique.

I couldn't figure out a way of doing it without removing the ID, which would have avoided all the other problems I'm facing. The base deduplication works, but adding the IDs back is the problem.

I know you can get an element from a specific spot with: ExampleList.get(arrayPosition).getJSON("element").

How can I add an element to an existing array element at a specific index position?

The function is large so I didn't want to post code, but if needed I can supply code snippets.