Filter expression with equals on array without match

Setup

Selector: $[?(@.key==43)]

[{"key": 42}]

Results

Consensus

[]

Not found consensus

This consensus applies for implementations which return a specific not found value if no match exists.

NOT_FOUND

Other responses

C (json-glib)

Not supported

Unable to compile selector `$[?(@.key==43)]': Invalid array index definition “?(@.key==43)]”

Kotlin (com.nfeld.jsonpathkt) ¹

Not supported

Unexpected char, char=?, index=2

Python (jsonpath-ng)

Not supported

JsonPathLexerError('Error on line 1, col 2: Unexpected character: ? ')

Python (jsonpath-rw)

Not supported

JsonPathLexerError('Error on line 1, col 2: Unexpected character: ? ')

Python (jsonpath2)

Not supported

line 1:10 extraneous input '=' expecting {'@', '$', 'true', 'false', 'null', '{', '[', STRING, NUMBER}
ValueError("line 1:10 extraneous input '=' expecting {'@', '$', 'true', 'false', 'null', '{', '[', STRING, NUMBER}")

Raku (JSON-Path)

Not supported

Evaluation of embedded Perl 6 code not allowed (construct with :allow-eval)

Errors

PHP (Goessner) ²

ArgumentCountError

Perl (JSON-Path)

non-safe evaluation, died at main.pl line 11.

Footnotes

• ¹ This implementation returns a single value where only one match is possible (instead of an array of a single value).
• ² This implementation returns a specific not found value if no match exists.
• ³ This implementation returns a specific not found value if a query that would regularly return a single match results in no match.