배열 안에서 2중 정렬을 하려는 경우에 유효한 함수
를 소개한다.

http://jp2.php.net/manual/ja/function.array-multisort.php 로부터 인용.

------------

php a-t-the-r-a-t-e chir.ag
06-Jan-2006 07:10
Re: phu at kungphu, 19-Dec-2005 11:36

asort($test) will not let me specify which columns to sort ASC/DESC, NUMERIC/STRING etc.

I have data similar to what you specified. Now I want to sort $test by points DESC and name ASC. Here's my function that does it, based on suggestions on this page. It uses array_multisort (and hence acts just like it: preserving string-keys etc.)

<?php

  function arrayColumnSort()
  {
    $n = func_num_args();
    $ar = func_get_arg($n-1);
    if(!is_array($ar))
      return false;

    for($i = 0; $i < $n-1; $i++)
      $col[$i] = func_get_arg($i);

    foreach($ar as $key => $val)
      foreach($col as $kkey => $vval)
        if(is_string($vval))
          ${"subar$kkey"}[$key] = $val[$vval];

    $arv = array();
    foreach($col as $key => $val)
      $arv[] = (is_string($val) ? ${"subar$key"} : $val);
    $arv[] = $ar;

    call_user_func_array("array_multisort", $arv);
    return $ar;
  }

  $test["pete"]['points']=1;
  $test["pete"]['name']='Peter';

  $test["mike"]['points']=5;
  $test["mike"]['name']='Mike';

  $test["zoo"]['points']=2;
  $test["zoo"]['name']='John Zoo';

  $test["ab"]['points']=2;
  $test["ab"]['name']='John Ab';

  $test1 = $test;

  asort($test1);

  $test2 = arrayColumnSort("points", SORT_DESC, SORT_NUMERIC, "name", SORT_ASC, SORT_STRING, $test);

  print_r($test1); // asort
  print_r($test2); // arrayColumnSort

?>

Output from asort:

Array
(
    [pete] => Array
        (
            [points] => 1
            [name] => Peter
        )

    [ab] => Array
        (
            [points] => 2
            [name] => John Ab
        )

    [zoo] => Array
        (
            [points] => 2
            [name] => John Zoo
        )

    [mike] => Array
        (
            [points] => 5
            [name] => Mike
        )

)

Output from arrayColumnSort:

Array
(
    [mike] => Array
        (
            [points] => 5
            [name] => Mike
        )

    [ab] => Array
        (
            [points] => 2
            [name] => John Ab
        )

    [zoo] => Array
        (
            [points] => 2
            [name] => John Zoo
        )

    [pete] => Array
        (
            [points] => 1
            [name] => Peter
        )

)