--TEST-- MongoDB\BSON\Undefined #001 --FILE-- $test) { $s = fromPHP($test); echo "Test#{$n} ", $json = toJSON($s), "\n"; $bson = fromJSON($json); $testagain = toPHP($bson); var_dump(toJSON(fromPHP($test)), toJSON(fromPHP($testagain))); var_dump((object)$test == (object)$testagain); } ?> ===DONE=== --EXPECT-- Test#0 { "undefined" : { "$undefined" : true } } string(41) "{ "undefined" : { "$undefined" : true } }" string(41) "{ "undefined" : { "$undefined" : true } }" bool(true) ===DONE===