recover data ajax symfony

I have a sql query in the symfony controller that returns me an array and I want to recover the data via ajax

  $statement = $connection->prepare("select name, first name from Contact WHERE name LIKE 'aaaa'");
    //$statement->bindValue('id', 123);
    $statement->execute();
    $results = $statement->fetchAll();

this request gets a array (registration list)

how I can treat using ajax result this is what I do but it does not work

success: function(data) {
            if (data != ''){
                $ulSub = $("#res");

                $.each(data, function (i,item) {
                    $ulSub.append( // append directly here
                            '<li class="ui-widget-content">' +dataa.nom, +dataa.prenom +'</li>');
                });
            }

I want to display the result in an html list