无法让类中的方法起作用

static private  function removeAccentedLetters($input){
    for ($i = 0; $i < strlen($input); $i++) {
        $input[$i]=self::simplify($input[$i]);
    }
    return $input;
}

static private function simplify($in){

   switch ($in) {
   case 'Á':
          return 'A';
   case 'á':
          return 'a';
   default:
         return $in;     
   }
}

This is the code. Doesn't work. Any thoughts? Oh yeah. It always enters the dafault exit for any input. perhaps it is somethig to do with how php handles chars X strings? I don't know.

Instead of switching the character itself, switch the character code. It's dangerous to embed ASCII Extended characters directly in a string, raw. Sometimes even the editor you are using to write the code may save the characters incorrectly, if you have the wrong encoding specified.

You should use str_replace instead:

$input = str_replace(array('Á', 'á'), array('A', 'a'), $input);

That does the exact same work as your switch statement.

Yeah. I changed the code slightly to this

        switch ($in) {
        case 'B':
            return 'A';
        case 'b':
            return 'a';
        default:
            return $in;     
    }

for testing purposes and it worked. Thanks to all.