regex to also match accented characters

Question

I have the following PHP code:

$search = "foo bar que";
$search_string = str_replace(" ", "|", $search);

$text = "This is my foo text with qué and other accented characters.";
$text = preg_replace("/$search_string/i", "<b>$0</b>", $text);

echo $text;

Obviously, "que" does not match "qué". How can I change that? Is there a way to make preg_replace ignore all accents?

The characters that have to match (Spanish):

á,Á,é,É,í,Í,ó,Ó,ú,Ú,ñ,Ñ

I don't want to replace all accented characters before applying the regex, because the characters in the text should stay the same:

"This is my foo text with qué and other accented characters."

and not

"This is my foo text with que and other accented characters."

Actually it's working for me. see screen shot:- http://prntscr.com/75gj1w — Alive to die - Anant, May 15 '15 at 12:28

score 3 · Answer 1 · answered May 15 '15 at 12:58

The solution I finally used:

$search_for_preg = str_ireplace(["e","a","o","i","u","n"],
                                ["[eé]","[aá]","[oó]","[ií]","[uú]","[nñ]"],
                                $search_string);

$text = preg_replace("/$search_for_preg/iu", "<b>$0</b>", $text)."\n";

score 1 · Answer 2 · answered May 15 '15 at 12:29

1

If you want to use the captured text in the replacement string, you have to use character classes in your $search variable (anyway, you set it manually):

$search = "foo bar qu[eé]"

And so on.

answered May 15 '15 at 12:29

Wiktor Stribiżew

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Alternatively, you could have some array that maps, say, `e` to `eé` and replace all occurrences of `vowel` with `"[" . $dict[$vowel] ."]"`. – Nic May 15 '15 at 12:32

score 1 · Accepted Answer · answered May 15 '15 at 12:42

1

$search = str_replace(
   ['a','e','i','o','u','ñ'],
   ['[aá]','[eé]','[ií]','[oó]','[uú]','[nñ]'],
   $search)

This and the same for upper case will complain your request. A side note: ñ replacemet sounds invalid to me, as 'niño' is totaly diferent from 'nino'

answered May 15 '15 at 12:42

Saic Siquot

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I use str_ireplace with your answer, that is exaclty what I needed! – Felix Bernhard May 15 '15 at 12:54
1

The website is for "lazy" people so it is correct that "n" matches "ñ" ;) – Felix Bernhard May 15 '15 at 12:56

Nic · Answer 4 · 2015-05-15T12:44:04.943

You could try defining an array like this:

$vowel_replacements = array(
    "e" => "eé",
    // Other letters mapped to their other versions
);

Then, before your preg_match call, do something like this:

foreach ($vowel_replacements as $vowel => $replacements) {
    str_replace($search_string, "$vowel", "[$replacements]");
}

If I'm remembering my PHP right, that should replace your vowels with a character class of their accented forms -- which will keep it in place. It also lets you change the search string far more easily; you don't have to remember to replaced the vowels with their character classes. All you have to remember is to use the non-accented form in your search string.

(If there's some special syntax I'm forgetting that does this without a foreach, please comment and let me know.)

regex to also match accented characters

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