What is the convention in JSON for empty vs. null?

Question

I know that in most programming scenarios, the preference is for empty collections to null collections when there are 0 elements. However, most languages that consume JSON

Answer 1

There is the question whether we want to differentiate between cases:

1. "phone" : "" = the value is empty

2. "phone" : null = the value for "phone" was not set yet

If we want differentiate I would use null for this. Otherwise we would need to add a new field like "isAssigned" or so. This is an old Database issue.