"Note: Variables of type resource couldn't be exported by this function." -php.net

Since a resource can’t be exported var_dump() replaces it with null. Good thing to know in those wtf moments.

php > $a = fopen('deleteme.php','r');

php > var_export($a);

NULL

php > var_export(is_resource($a));

true

php > var_dump($a);

resource(2) of type (stream)

php >