PHP - warning - Undefined property: stdClass - fix?

I get this warning in my error logs and wanted to know how to correct this issues in my code.

Warning: PHP Notice: Undefined property: stdClass::$records in script.php on line 440

Some Code:

// Parse object to get account id's
// The response doesn't have the records attribute sometimes.
$role_arr = getRole($response->records);  // Line 440 

Response if records exists

stdClass Object
(
    [done] => 1
    [queryLocator] =>
    [records] => Array
        (
            [0] => stdClass Object
                (
                    [type] => User
                    [Id] =>
                    [any] => stdClass Object
                        (
                            [type] => My Role
                            [Id] =>
                            [any] => <sf:Name>My Name</sf:Name>
                        )

                )

        )

    [size] => 1
)

Response if records does not exist

stdClass Object
(
    [done] => 1
    [queryLocator] =>
    [size] => 0
)

I was thinking something like array_key_exists() functionality but for objects, anything? or am I going about this the wrong way?