How to remove diacritics from text?

Question

I am making a swedish website, and swedish letters are å, ä, and ö.

I need to make a string entered by a user to become url-safe with PHP.

Basically, need to

Answer 1

If intl php extension is enabled, you can use Transliterator like this :

protected function removeDiacritics($string)
{
    $transliterator = \Transliterator::create('NFD; [:Nonspacing Mark:] Remove; NFC;');
    return $transliterator->transliterate($string);
}

To remove other special chars (not diacritics only like 'æ')

protected function removeDiacritics($string)
{
    $transliterator = \Transliterator::createFromRules(
        ':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: NFC;',
        \Transliterator::FORWARD
    );
    return $transliterator->transliterate($string);
}

Answer 2

If you're just interested in making things URL safe, then you want urlencode.

Returns a string in which all non-alphanumeric characters except -_. have been replaced with a percent (%) sign followed by two hex digits and spaces encoded as plus (+) signs. It is encoded the same way that the posted data from a WWW form is encoded, that is the same way as in application/x-www-form-urlencoded media type. This differs from the » RFC 1738 encoding (see rawurlencode()) in that for historical reasons, spaces are encoded as plus (+) signs.

If you really want to strip all non A-Z, a-z, 1-9 (what's wrong with 0, by the way?), then you want:

$mynewstring = preg_replace('/[^A-Za-z1-9]/', '', $str);

Answer 3

as simple as

 $str = str_replace(array('å', 'ä', 'ö'), array('a', 'a', 'o'), $str); 
 $str = preg_replace('/[^a-z0-9]+/', '_', strtolower($str));

assuming you use the same encoding for your data and your code.

Answer 4

// normalize data (remove accent marks) using PHP's *intl* extension
$data = normalizer_normalize($data);

// replace everything NOT in the sets you specified with an underscore
$data = preg_replace("#[^A-Za-z1-9]#","_", $data);

Answer 5

Use iconv to convert strings from a given encoding to ASCII, then replace non-alphanumeric characters using preg_replace:

$input = 'räksmörgås och köttbullar'; // UTF8 encoded
$input = iconv('UTF-8', 'ASCII//TRANSLIT', $input);
$input = preg_replace('/[^a-zA-Z0-9]/', '_', $input);
echo $input;

Result:

raksmorgas_och_kottbullar

Answer 6

One simple solution is to use str_replace function with search and replace letter arrays.