wp-includes/rest-api.php:1618Determines if a given value is object-like.
$maybe_objectmixedboolfunction rest_is_object( $maybe_object ) { if ( '' === $maybe_object ) { return true; } if ( $maybe_object instanceof stdClass ) { return true; } if ( $maybe_object instanceof JsonSerializable ) { $maybe_object = $maybe_object->jsonSerialize(); } return is_array( $maybe_object );}Introduced in 5.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/rest-api.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.