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14 years ago
Sorting UTF-8 by arbitrary order:



<?php

mb_internal_encoding("UTF-8");



class utf_8_german

{

  // everything else is sorted at the end

  static $order = '0123456789AaÄäBbCcDdEeFfGgHhIiJjKkLlMm

NnOoÖöPpQqRrSsßTtUuÜüVvWwXxYyZz';

  static $char2order;

  

  static function cmp($a, $b) {

    if ($a == $b) {

        return 0;

    }

    

    // lazy init mapping

    if (empty(self::$char2order))

    {

      $order = 1;

      $len = mb_strlen(self::$order);

      for ($order=0; $order<$len; ++$order)

      {

        self::$char2order[mb_substr(self::$order, $order, 1)] = $order;

      }

    }

    

    $len_a = mb_strlen($a);

    $len_b = mb_strlen($b);

    $max=min($len_a, $len_b);

    for($i=0; $i<$max; ++$i)

    {

      $char_a= mb_substr($a, $i, 1);

      $char_b= mb_substr($b, $i, 1);

      

      if ($char_a == $char_b) continue;

      $order_a = (isset(self::$char2order[$char_a])) ? self::$char2order[$char_a] : 9999;

      $order_b = (isset(self::$char2order[$char_b])) ? self::$char2order[$char_b] : 9999;

      

      return ($order_a < $order_b) ? -1 : 1;

    }

    return ($len_a < $len_b) ? -1 : 1;

  }

}



// usage example:



$t = array(

  'Birnen', 'Birne', 'Äpfel', 'Apfel',

);



uasort($t, 'utf_8_german::cmp');

echo '$t: <pre>'.htmlspecialchars(print_r($t,true),null,'UTF-8').'</pre>';

?>
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