How to remove accents and turn letters into “plain

Question

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• PHP: Replace umlauts with closest 7-bit ASCII equivalent in an UTF-8 string 7 answers

What is the most efficient way to remove accents from a string e.g. ÈâuÑ becomes Eaun?

Is there a simple, built in way that I'm missing or a regular expression?

Answer 1

You can use iconv to transliterate the characters to plain US-ASCII and then use a regular expression to remove non-alphabetic characters:

preg_replace('/[^a-z]/i', '', iconv("UTF-8", "US-ASCII//TRANSLIT", $text))

Another way would be using the Normalizer to normalize to the Normalization Form KD (NFKD) and then remove the mark characters:

preg_replace('/\p{Mn}/u', '', Normalizer::normalize($text, Normalizer::FORM_KD))

Answer 2

If you have iconv installed, try this (the example assumes your input string is in UTF-8):

echo iconv('UTF-8', 'ASCII//TRANSLIT', $string);

(iconv is a library to convert between all kinds of encodings; it's efficient and included with many PHP distributions by default. Most of all, it's definitely easier and more error-proof than trying to roll your own solution (did you know that there's a "Latin letter N with a curl"? Me neither.))

Answer 3

Reposting this on request of @palantir ...

I find iconv completely unreliable, and I dislike preg_replace solutions and big arrays ... so my favorite way (and the only reliable method I've found) is ...

function toASCII( $str )
{
    return strtr(utf8_decode($str), 
        utf8_decode(
        'ŠŒŽšœžŸ¥µÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýÿ'),
        'SOZsozYYuAAAAAAACEEEEIIIIDNOOOOOOUUUUYsaaaaaaaceeeeiiiionoooooouuuuyy');
}

Answer 4

I found a solution, that worked in all my test-cases (copied from http://php.net/manual/en/transliterator.transliterate.php):

var_dump(transliterator_transliterate('Any-Latin; Latin-ASCII; [\u0080-\u7fff] remove',
    "A æ Übérmensch på høyeste nivå! И я люблю PHP! есть. fi ¦"));
// string(50) "A ae Ubermensch pa hoyeste niva! I a lublu PHP! est. fi "

see: http://www.php.net/normalizer

EDIT: This solution is independent of the locale set using setlocale(). Another benefit over iconv() is, that even non-latin characters are not ignored.

EDIT2: I discovered, that there are some characters, that are not covered by the transliteration I posted originally. Any-Latin translates the cyrillic character ь to a character, that doesn't fit into a latin character-set: ʹ (http://en.wikipedia.org/wiki/Prime_%28symbol%29). I've added [\u0100-\u7fff] remove to remove all these non-latin characters. I also added a test to the text ;)

I suggest, that they mean the latin alphabet and not one of the latin character-sets by Latin here. But anyways - in my opinion, they should transliterate it to something ASCII then in Latin-ASCII ...

EDIT3: Sorry for another change here. I had to take the characters down to u0080 instead of u0100, to get only ASCII characters as output. The test above is updated.

Answer 5

Note: I'm reposting this from another similar question in the hope that it's helpful to others.

I ended up writing a PHP library based on URLify.js from the Django project, since I found iconv() to be too incomplete. You can find it here:

https://github.com/jbroadway/urlify

Handles Latin characters as well as Greek, Turkish, Russian, Ukrainian, Czech, Polish, and Latvian.