Array_walk通过10000个项目。 优化可能吗？

My code is looping through an array with array_walk and that array contains about 10.000 items. The query takes 5.19 seconds to fetch the records but walking through the array takes 19.86 seconds. There probably isn't anything I can do to speed things up?

The questions are returned in json and used by the jquery dataTables plugin to create the table. The plugin doesn't seem to have a problem with that many entries (at least not on firefox).

I'm using the laravel framework. See controller code below

$start = microtime(true);
$questions = Question::with(array('tags', 'category'))->get();
$now = microtime(true) - $start;
echo "<h3>FETCHED QUESTIONS: $now</h3>";
array_walk($questions, function(&$value, $key) {
    $value = $value->to_array();
    if (empty($value['category'])) $value['category'] = '--';
    if (empty($value['difficulty'])) $value['difficulty'] = '--';
    $value['difficulty'] = HTML::difficulty_label($value['difficulty']);
    $value['approved'] = HTML::on_off_images($value['approved'], 'approved', 'declined');
    $value['active'] = HTML::on_off_images($value['active'], 'active', 'disabled');
    $value['edit_link'] = '<a href="' . URL::to('admin/editquestion/' . $value['id']) . '">' . HTML::image('img/icons/pencil.png', 'edit question') ; '</a>';
});

$spent = microtime(true) - $start - $now;
$now = microtime(true) - $start;
echo "<h3>AFTER WALK: $now ($spent)</h3>";
$out = array('aaData' => $questions);
return json_encode($out);

Just loop the array yourself with foreach to avoid the penalty of making 10000 function calls:

foreach($questions as &$value) {
    $value = $value->to_array();
    if (empty($value['category'])) $value['category'] = '--';
    if (empty($value['difficulty'])) $value['difficulty'] = '--';
    $value['difficulty'] = HTML::difficulty_label($value['difficulty']);
    $value['approved'] = HTML::on_off_images($value['approved'], 'approved', 'declined');
    $value['active'] = HTML::on_off_images($value['active'], 'active', 'disabled');
    $value['edit_link'] = '<a href="' . URL::to('admin/editquestion/' . $value['id']) . '">' . HTML::image('img/icons/pencil.png', 'edit question') ; '</a>';
}