need help grouping a php array

Question

hi all, i've got a mysql query which spits out the following array:

Array
(
    [0] => stdClass Object
        (
            [item1] => foo 0
            [item2] => bar 0
            [catid] => 3
        )

    [1] => stdClass Object
        (
            [item1] => foo 1
            [item2] => bar 1
            [catid] => 7
        )

    [2] => stdClass Object
        (
            [item1] => foo 2
            [item2] => bar 2
            [catid] => 10
        )

    [3] => stdClass Object
        (
            [item1] => foo 3
            [item2] => bar 3
            [catid] => 7
        )

)

I was wondering if it was possible to group the array by "category", so instead of duplicate catids, there would be one catid with each object inside it.. if that makes sense? So say catid 7 would only appear once, with the two item1/item2 inside it.

Answer 1

How about this?

foreach($results as $result) {
    $by_category[$result->catid][] = $result;
}

print_r($by_category);

Answer 2

$ret = array();
foreach ($array as $value) {
  foreach ($value as $key => $item) {
      if ($key == 'catid') continue;
      $ret[$value['catid']][] = $item;
  }
}