[gavino]

Regarding the "index" key, there are some JSON parsers for languages like Swift that will rearrange your JSON. By adding the index key, you'll still be able to sort after parsing.

Also, thanks, it's really cool to see people liking this :)

[JelteF]

They might rearrange keys in a JSON object, but in an array they should be preserved in order as according to the spec[1]. If Swift does this (which I can't really check) than this would be a bug.

[1] http://www.json.org/: An array is an ordered collection of values. An array begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma).

[chriswarbo]

Yes, the order of elements in an array should always be preserved. For example, we might be expecting the first element to be a name, the second to be a date of birth, etc. We should use an object for that, but that's for reasons of readability, extensibility, etc. rather than array semantics being unsuitable.

Also, jq has a `--sort-keys` option which tries to make the output as reproducible/canonical as possible. From the manual:

> The keys are sorted "alphabetically", by unicode codepoint order. This is not an order that makes particular sense in any particular language, but you can count on it being the same for any two objects with the same set of keys, regardless of locale settings.

It would be strange for a JSON tool to go to such lengths to normalise data, if array order were unpredictable.