[_ZeD_]

while this is true, I think it's irrelevant: the "trick" is about "abusing"

* the fact parser work from top to bottom of the text

AND

* the fact that assigning the same key many times with different values update the key with the last value

your quote regards the order in witch the different keys are saved.

[masklinn]

Both are only "correct" for specific implementation, this is not specified behavior (and duplicate keys is strongly recommended against by the key)

[_ZeD_]

absolutely. This is nothing more than a clever trick, but I would never rely on it.

Honestly, tough, I think all major JSON parser behave following the two assumption.

[masklinn]

streaming parsers can't follow the assumption short of becoming useless. They're either going to send only the first instance or going to send two different events.