I am trying to replace accented characters with the normal replacements. Below is what I am currently doing.

    $string = "Éric Cantona";
    $strict = strtolower($string);

    echo "After Lower: ".$strict;

    $patterns[0] = '/[á|â|à|å|ä]/';
    $patterns[1] = '/[ð|é|ê|è|ë]/';
    $patterns[2] = '/[í|î|ì|ï]/';
    $patterns[3] = '/[ó|ô|ò|ø|õ|ö]/';
    $patterns[4] = '/[ú|û|ù|ü]/';
    $patterns[5] = '/æ/';
    $patterns[6] = '/ç/';
    $patterns[7] = '/ß/';
    $replacements[0] = 'a';
    $replacements[1] = 'e';
    $replacements[2] = 'i';
    $replacements[3] = 'o';
    $replacements[4] = 'u';
    $replacements[5] = 'ae';
    $replacements[6] = 'c';
    $replacements[7] = 'ss';

    $strict = preg_replace($patterns, $replacements, $strict);
    echo "Final: ".$strict;

This gives me:

    After Lower: éric cantona
    Final: ric cantona

The above gives me ric cantona I want the output to be eric cantona.

can anyone help me with where I am going wrong?


Solution 1:

I have tried all sorts based on the variations listed in the answers, but the following worked:

$unwanted_array = array(    'Š'=>'S', 'š'=>'s', 'Ž'=>'Z', 'ž'=>'z', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'A', 'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E',
                            'Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U',
                            'Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a', 'æ'=>'a', 'ç'=>'c',
                            'è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i', 'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o',
                            'ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'ý'=>'y', 'þ'=>'b', 'ÿ'=>'y' );
$str = strtr( $str, $unwanted_array );

Solution 2:

To remove the diacritics, use iconv:

$val = iconv('ISO-8859-1','ASCII//TRANSLIT',$val);

or

$val = iconv('UTF-8','ASCII//TRANSLIT',$val);

note that php has some weird bug in that it (sometimes?) needs to have a locale set to make these conversions work, using setlocale().

edit tested, it gets all of your diacritics out of the box:

$val = "á|â|à|å|ä ð|é|ê|è|ë í|î|ì|ï ó|ô|ò|ø|õ|ö ú|û|ù|ü æ ç ß abc ABC 123";
echo iconv('UTF-8','ASCII//TRANSLIT',$val); 

output (updated 2019-12-30)

a|a|a|a|a d|e|e|e|e i|i|i|i o|o|o|o|o|o u|u|u|u ae c ss abc ABC 123

Note that ð is correctly transliterated to d instead of o, as in the accepted answer.

Solution 3:

I just came accross the answer from Lizard which is extremely helpful - especially when you do some sorting. Isn't is beautiful how many chars we need to say mostly the same ;)

If anyone else if looking for a all-in solution (as far as the comments above tell), here's the copy&paste:

/**
 * Replace language-specific characters by ASCII-equivalents.
 * @param string $s
 * @return string
 */
public static function normalizeChars($s) {
    $replace = array(
        'ъ'=>'-', 'Ь'=>'-', 'Ъ'=>'-', 'ь'=>'-',
        'Ă'=>'A', 'Ą'=>'A', 'À'=>'A', 'Ã'=>'A', 'Á'=>'A', 'Æ'=>'A', 'Â'=>'A', 'Å'=>'A', 'Ä'=>'Ae',
        'Þ'=>'B',
        'Ć'=>'C', 'ץ'=>'C', 'Ç'=>'C',
        'È'=>'E', 'Ę'=>'E', 'É'=>'E', 'Ë'=>'E', 'Ê'=>'E',
        'Ğ'=>'G',
        'İ'=>'I', 'Ï'=>'I', 'Î'=>'I', 'Í'=>'I', 'Ì'=>'I',
        'Ł'=>'L',
        'Ñ'=>'N', 'Ń'=>'N',
        'Ø'=>'O', 'Ó'=>'O', 'Ò'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'Oe',
        'Ş'=>'S', 'Ś'=>'S', 'Ș'=>'S', 'Š'=>'S',
        'Ț'=>'T',
        'Ù'=>'U', 'Û'=>'U', 'Ú'=>'U', 'Ü'=>'Ue',
        'Ý'=>'Y',
        'Ź'=>'Z', 'Ž'=>'Z', 'Ż'=>'Z',
        'â'=>'a', 'ǎ'=>'a', 'ą'=>'a', 'á'=>'a', 'ă'=>'a', 'ã'=>'a', 'Ǎ'=>'a', 'а'=>'a', 'А'=>'a', 'å'=>'a', 'à'=>'a', 'א'=>'a', 'Ǻ'=>'a', 'Ā'=>'a', 'ǻ'=>'a', 'ā'=>'a', 'ä'=>'ae', 'æ'=>'ae', 'Ǽ'=>'ae', 'ǽ'=>'ae',
        'б'=>'b', 'ב'=>'b', 'Б'=>'b', 'þ'=>'b',
        'ĉ'=>'c', 'Ĉ'=>'c', 'Ċ'=>'c', 'ć'=>'c', 'ç'=>'c', 'ц'=>'c', 'צ'=>'c', 'ċ'=>'c', 'Ц'=>'c', 'Č'=>'c', 'č'=>'c', 'Ч'=>'ch', 'ч'=>'ch',
        'ד'=>'d', 'ď'=>'d', 'Đ'=>'d', 'Ď'=>'d', 'đ'=>'d', 'д'=>'d', 'Д'=>'D', 'ð'=>'d',
        'є'=>'e', 'ע'=>'e', 'е'=>'e', 'Е'=>'e', 'Ə'=>'e', 'ę'=>'e', 'ĕ'=>'e', 'ē'=>'e', 'Ē'=>'e', 'Ė'=>'e', 'ė'=>'e', 'ě'=>'e', 'Ě'=>'e', 'Є'=>'e', 'Ĕ'=>'e', 'ê'=>'e', 'ə'=>'e', 'è'=>'e', 'ë'=>'e', 'é'=>'e',
        'ф'=>'f', 'ƒ'=>'f', 'Ф'=>'f',
        'ġ'=>'g', 'Ģ'=>'g', 'Ġ'=>'g', 'Ĝ'=>'g', 'Г'=>'g', 'г'=>'g', 'ĝ'=>'g', 'ğ'=>'g', 'ג'=>'g', 'Ґ'=>'g', 'ґ'=>'g', 'ģ'=>'g',
        'ח'=>'h', 'ħ'=>'h', 'Х'=>'h', 'Ħ'=>'h', 'Ĥ'=>'h', 'ĥ'=>'h', 'х'=>'h', 'ה'=>'h',
        'î'=>'i', 'ï'=>'i', 'í'=>'i', 'ì'=>'i', 'į'=>'i', 'ĭ'=>'i', 'ı'=>'i', 'Ĭ'=>'i', 'И'=>'i', 'ĩ'=>'i', 'ǐ'=>'i', 'Ĩ'=>'i', 'Ǐ'=>'i', 'и'=>'i', 'Į'=>'i', 'י'=>'i', 'Ї'=>'i', 'Ī'=>'i', 'І'=>'i', 'ї'=>'i', 'і'=>'i', 'ī'=>'i', 'ij'=>'ij', 'IJ'=>'ij',
        'й'=>'j', 'Й'=>'j', 'Ĵ'=>'j', 'ĵ'=>'j', 'я'=>'ja', 'Я'=>'ja', 'Э'=>'je', 'э'=>'je', 'ё'=>'jo', 'Ё'=>'jo', 'ю'=>'ju', 'Ю'=>'ju',
        'ĸ'=>'k', 'כ'=>'k', 'Ķ'=>'k', 'К'=>'k', 'к'=>'k', 'ķ'=>'k', 'ך'=>'k',
        'Ŀ'=>'l', 'ŀ'=>'l', 'Л'=>'l', 'ł'=>'l', 'ļ'=>'l', 'ĺ'=>'l', 'Ĺ'=>'l', 'Ļ'=>'l', 'л'=>'l', 'Ľ'=>'l', 'ľ'=>'l', 'ל'=>'l',
        'מ'=>'m', 'М'=>'m', 'ם'=>'m', 'м'=>'m',
        'ñ'=>'n', 'н'=>'n', 'Ņ'=>'n', 'ן'=>'n', 'ŋ'=>'n', 'נ'=>'n', 'Н'=>'n', 'ń'=>'n', 'Ŋ'=>'n', 'ņ'=>'n', 'ʼn'=>'n', 'Ň'=>'n', 'ň'=>'n',
        'о'=>'o', 'О'=>'o', 'ő'=>'o', 'õ'=>'o', 'ô'=>'o', 'Ő'=>'o', 'ŏ'=>'o', 'Ŏ'=>'o', 'Ō'=>'o', 'ō'=>'o', 'ø'=>'o', 'ǿ'=>'o', 'ǒ'=>'o', 'ò'=>'o', 'Ǿ'=>'o', 'Ǒ'=>'o', 'ơ'=>'o', 'ó'=>'o', 'Ơ'=>'o', 'œ'=>'oe', 'Œ'=>'oe', 'ö'=>'oe',
        'פ'=>'p', 'ף'=>'p', 'п'=>'p', 'П'=>'p',
        'ק'=>'q',
        'ŕ'=>'r', 'ř'=>'r', 'Ř'=>'r', 'ŗ'=>'r', 'Ŗ'=>'r', 'ר'=>'r', 'Ŕ'=>'r', 'Р'=>'r', 'р'=>'r',
        'ș'=>'s', 'с'=>'s', 'Ŝ'=>'s', 'š'=>'s', 'ś'=>'s', 'ס'=>'s', 'ş'=>'s', 'С'=>'s', 'ŝ'=>'s', 'Щ'=>'sch', 'щ'=>'sch', 'ш'=>'sh', 'Ш'=>'sh', 'ß'=>'ss',
        'т'=>'t', 'ט'=>'t', 'ŧ'=>'t', 'ת'=>'t', 'ť'=>'t', 'ţ'=>'t', 'Ţ'=>'t', 'Т'=>'t', 'ț'=>'t', 'Ŧ'=>'t', 'Ť'=>'t', '™'=>'tm',
        'ū'=>'u', 'у'=>'u', 'Ũ'=>'u', 'ũ'=>'u', 'Ư'=>'u', 'ư'=>'u', 'Ū'=>'u', 'Ǔ'=>'u', 'ų'=>'u', 'Ų'=>'u', 'ŭ'=>'u', 'Ŭ'=>'u', 'Ů'=>'u', 'ů'=>'u', 'ű'=>'u', 'Ű'=>'u', 'Ǖ'=>'u', 'ǔ'=>'u', 'Ǜ'=>'u', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'У'=>'u', 'ǚ'=>'u', 'ǜ'=>'u', 'Ǚ'=>'u', 'Ǘ'=>'u', 'ǖ'=>'u', 'ǘ'=>'u', 'ü'=>'ue',
        'в'=>'v', 'ו'=>'v', 'В'=>'v',
        'ש'=>'w', 'ŵ'=>'w', 'Ŵ'=>'w',
        'ы'=>'y', 'ŷ'=>'y', 'ý'=>'y', 'ÿ'=>'y', 'Ÿ'=>'y', 'Ŷ'=>'y',
        'Ы'=>'y', 'ž'=>'z', 'З'=>'z', 'з'=>'z', 'ź'=>'z', 'ז'=>'z', 'ż'=>'z', 'ſ'=>'z', 'Ж'=>'zh', 'ж'=>'zh'
    );
    return strtr($s, $replace);
}

Note some slight changes regarding the German umlauts (ä => ae)

Edit: Included more characters based on the posting from user3682119 (except for the copyright symbol) and the comment from daker.

Solution 4:

In PHP 5.4 the intl extension provides a new class named Transliterator.

I believe that's the best way to remove diacritics for two reasons:

  1. Transliterator is based on ICU, so you're using the tables of the ICU library. ICU is a great project, developed over the year to provide comprehensive tables and functionalities. Whatever table you want to write yourself, it will never be as complete as the one from ICU.

  2. In UTF-8, characters could be represented differently. For example, the character ñ could be saved as a single (multi-byte) character, or as the combination of characters ˜ (multibyte) and n. In addition to this, some characters in Unicode are homograph: they look the same while having different codepoints. For this reason it's also important to normalize the string.

Here's a sample code, taken from an old answer of mine:

<?php
$transliterator = Transliterator::createFromRules(':: NFD; :: [:Nonspacing Mark:] Remove; :: NFC;', Transliterator::FORWARD);
$test = ['abcd', 'èe', '€', 'àòùìéëü', 'àòùìéëü', 'tiësto'];
foreach($test as $e) {
    $normalized = $transliterator->transliterate($e);
    echo $e. ' --> '.$normalized."\n";
}
?>

Result:

abcd --> abcd
èe --> ee
€ --> €
àòùìéëü --> aouieeu
àòùìéëü --> aouieeu
tiësto --> tiesto

The first argument for the Transliterator class performs the removal of diacritics as well as the normalization of the string.