2차원 배열 정렬 함수 array_orderby의 사용 사례에 대한 자세한 설명

<?php
/**
I came up with an easy way to sort database-style results. This does what example 3 does, except it takes care of creating those intermediate arrays for you before passing control on to array_multisort(). 
*/
function array_orderby()
{
  $args = func_get_args();
  $data = array_shift($args);
  foreach ($args as $n => $field) {
    if (is_string($field)) {
      $tmp = array();
      foreach ($data as $key => $row)
        $tmp[$key] = $row[$field];
      $args[$n] = $tmp;
      }
  }
  $args[] = &$data;
  call_user_func_array(&#39;array_multisort&#39;, $args);
  return array_pop($args);
}
/*
The sorted array is now in the return value of the function instead of being passed by reference.
*/
$data[] = array(&#39;volume&#39; => 67, &#39;edition&#39; => 2);
$data[] = array(&#39;volume&#39; => 86, &#39;edition&#39; => 1);
$data[] = array(&#39;volume&#39; => 85, &#39;edition&#39; => 6);
$data[] = array(&#39;volume&#39; => 98, &#39;edition&#39; => 2);
$data[] = array(&#39;volume&#39; => 86, &#39;edition&#39; => 6);
$data[] = array(&#39;volume&#39; => 67, &#39;edition&#39; => 7);
// Pass the array, followed by the column names and sort flags
$sorted = array_orderby($data, &#39;volume&#39;, SORT_DESC, &#39;edition&#39;, SORT_ASC);
print_r($sorted)
?>

Array
(
  [0] => Array
    (
      [volume] => 98
      [edition] => 2
    )
  [1] => Array
    (
      [volume] => 86
      [edition] => 1
    )
  [2] => Array
    (
      [volume] => 86
      [edition] => 6
    )
  [3] => Array
    (
      [volume] => 85
      [edition] => 6
    )
  [4] => Array
    (
      [volume] => 67
      [edition] => 2
    )
  [5] => Array
    (
      [volume] => 67
      [edition] => 7
    )
)