Datatable return undefined offset but it return the data when I dd()

I wanna show data in datatable. it always return "undefined offset". but when I do "dd()" the data is exist. this is my code :

->editColumn('role', function($data){
            // dd($data->user->roles[0]['name']); //when I dd the data is exist
            return $data->user->roles[0]["name"]; //always undefined offset here
            }
        )

pls anyone help me.. thanks in advance.

via Chebli Mohamed