<?php
$array = [
'foo',
123,
4294967295,
new MongoDB\BSON\ObjectId('56315a7c6118fd1b920270b1'),
];
$packedArray = MongoDB\BSON\PackedArray::fromPHP($array);
echo $packedArray->toRelaxedExtendedJSON(), "\n";
?>
The above example will output:
[ "foo", 123, 4294967295, { "$oid" : "56315a7c6118fd1b920270b1" } ]