The issue is not about forgetting something. XML elements are self-contained, you don't need to separate them, thus you don't need to known the context. If you generate XML programmatically, each function can just push its object into the stream and be done. With JSON you need to know if your object is last or first at this level of hierarchy, so you know if you need to insert a comma or not.
Commas were meant to be used in code that you actually type. Using them as separators in a format that is meant to be produced and consumed by computers is clear, simple, and wrong.
Commas were meant to be used in code that you actually type. Using them as separators in a format that is meant to be produced and consumed by computers is clear, simple, and wrong.