[taeric]

The spec does call out that some parsers deal with this. And since it is javascript based, leniency is the norm.

That is, you could rely on this and but be aware of it, is my point. Firefox, for example, will happily take an object with duplicates and report only the last one.

[Splognosticus]

Well, by definition "unordered" means you can't count on any particular order. So while parsers may indeed preserve order, anything that relies on it is in violation of the standard.

That said, I agree that being aware of this is important if you're emitting JSON. You'd think nobody would ever address a JSON object by its ordinal position, but programmers are lazy and worse, think they're clever. :)

[taeric]

Exactly that. I did not mean to disagree that it is somewhat wrong. Just feels dangerous, as behavior could change with no side channel warnings.