====== PHP ======

== Replace umlauts ==

**!! This is really old, don't use it !!** // see comment below //

  function convertUmlaute($text){
     $pattern1="/ä/";
     $replace1="ä";
     $text=preg_replace($pattern1,$replace1, $text);
     $pattern2="/ö/";
     $replace2="ö";
     $text=preg_replace($pattern2,$replace2, $text);
     $pattern3="/ü/";
     $replace3="ü";
     $text=preg_replace($pattern3,$replace3, $text);
     $pattern1a="/Ä/";
     $replace1a="Ä";
     $text=preg_replace($pattern1a,$replace1a, $text);
     $pattern2a="/Ö/";
     $replace2a="Ö";
     $text=preg_replace($pattern2a,$replace2a, $text);
     $pattern3a="/Ü/";
     $replace3a="Ü";
     $text=preg_replace($pattern3a,$replace3a, $text);
     $pattern4="/ß/";
     $replace4="ß";
     $text=preg_replace($pattern4,$replace4, $text);
     return $text;
  }

This function uses preg_replace, which works with regular expressions. For better performance I recommend to use str_replace. A short example:
  $text = str_replace("ä", "ä", $text);