Does JSON Maintain Order in Lists?

Preserving Order in JSON Structures

Question: Regarding JSON lists, specifically, do they maintain the original order of elements?

Answer: Yes, the ordering of elements within JSON lists is strictly preserved. This aspect is explicitly stated in RFC 7159 -The JavaScript Object Notation (JSON) Data Interchange Format.

While JSON objects possess an unordered structure, where the order of name/value pairs is not guaranteed, arrays (lists) are designated as "ordered sequences" in the RFC. This means that the sequence of values in a JSON list is preserved and respected.

It's important to note that some implementations may extend this ordering guarantee to JSON object properties as well, but this is not a standard requirement and cannot be assumed. Therefore, it's safer to rely solely on the guaranteed order of elements in JSON arrays when the order is crucial.

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