Replacing accented characters php

Question

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

    $string = \"Éric Cantona\";
    $strict = st         


        

Answer 1

So I found this on php.net page for preg_replace function

// replace accented chars

$string = "Zacarías Ferreíra"; // my definition for string variable
$accents = '/&([A-Za-z]{1,2})(grave|acute|circ|cedil|uml|lig);/';

$string_encoded = htmlentities($string,ENT_NOQUOTES,'UTF-8');

$string = preg_replace($accents,'$1',$string_encoded);

If you have encoding issues you may get someting like this "Zacarías Ferreíra", just decode the string and use said code above

$string = utf8_decode("Zacarías Ferreíra");

Answer 2

I've searched and your idea for accent striping is quite awesome and cost-effective but your regex is wrongly done and misses 2 extra params. Long story short the regex must be:

$patterns[0] = '/[áâàåä]/ui';
$patterns[1] = '/[ðéêèë]/ui';
$patterns[2] = '/[íîìï]/ui';
$patterns[3] = '/[óôòøõö]/ui';
$patterns[4] = '/[úûùü]/ui';
$patterns[5] = '/æ/ui';
$patterns[6] = '/ç/ui';
$patterns[7] = '/ß/ui';
$replacements[0] = 'a';
$replacements[1] = 'e';
$replacements[2] = 'i';
$replacements[3] = 'o';
$replacements[4] = 'u';
$replacements[5] = 'ae';
$replacements[6] = 'c';
$replacements[7] = 'ss';

As you can see is quite similar but the most important thing is the paramas after the second slash of the regular expression. When a regualr expression is like this /[someCoolRegex]/ui the u specifies that it must use unicode and the i specifies that is case insensitive, I've tested my own and with the ansewer in this forum I must say is more cost efective than using strtr.

Hope someone reads this answer.

Answer 3

I found this way to be a good one, without having to worry too much about charsets and arrays:

function replace_accents($str) {
   $str = htmlentities($str, ENT_COMPAT, "UTF-8");
   $str = preg_replace('/&([a-zA-Z])(uml|acute|grave|circ|tilde);/','$1',$str);
   return html_entity_decode($str);
}

Answer 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.

Answer 5

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.

Answer 6

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 );