I have the following if condition:

```
if ( 
    $items[ $count + 1 ]->menu_item_parent != $parent_id && 
    $submenu && 
    $items[ $count + 1 ]->menu_item_parent != $item->ID) {

    //something

}

```

I get the notice:

```
Undefined offset: 13

```

So I assume the 13 does not exist in the `$items` array and it can be avoided by checking with `in_array`. However I'm unsure how I can use that function in the above condition.