mb_substr

(PHP 4 >= 4.0.6, PHP 5)

mb_substr — Lit une sous-chaîne

Description

string mb_substr ( string $str , int $start [, int $length [, string $encoding ]] )

Effectue une opération de type substr() basée sur le nombre de caractères. La position est celle depuis le début de la chaîne de caractères str. La position du premier caractère est 0, le second, un, etc...

Liste de paramètres

str: La chaîne à extraire depuis la sous-chaîne.
start: Position du premier caractère à utiliser depuis str.
length: Nombre maximal de caractères à utiliser depuis str.
encoding: Le paramètre encoding est l'encodage des caractères. S'il est omis, l'encodage de caractres interne sera utilisé.

Valeurs de retour

mb_substr() retourne la portion de la chaîne str qui commence au caractère start et a la longueur de length caractères.

Voir aussi

mb_strcut() - Coupe une partie de chaîne
mb_internal_encoding() - Lit/modifie l'encodage interne

Pspell

mb_substr_count

[edit] Last updated: Fri, 10 Feb 2012

add a note User Contributed Notes mb_substr

p dot assenov at aip-solutions dot com 02-Dec-2011 10:17


I'm trying to capitalize only the first character of the string and tried some of the examples above but they didn't work. It seems mb_substr() cannot calculate the length of the string in multi-byte encoding (UTF-8) and it should be set explicitly. Here is the corrected version:





<?php


function mb_ucfirst($str, $enc = 'utf-8') {


    return mb_strtoupper(mb_substr($str, 0, 1, $enc), $enc).mb_substr($str, 1, mb_strlen($str, $enc), $enc);


}


?>





cheers!

levani9191 at gmail dot com 18-Jul-2010 05:37


A simple code that check if the latest symbol in the string is a question mark and adds one if it doesn't...



<?php $string = (mb_substr($string, -1, 1, 'UTF-8') != '?') ? $string.'?' : $string; ?>

Anonymous 26-Feb-2010 06:15


If start  is negative, the returned string will start at the start'th character from the end of string

dziamid at gmail dot com 06-Feb-2009 09:27


Here is my solution to highlighting search queries in multibyte text:



<?php

function mb_highlight($data, $query, $ins_before, $ins_after)

{

 $result = '';

 while (($poz = mb_strpos(mb_strtolower($data), mb_strtolower($query))) !== false)

 {

       $query_len = mb_strlen ($query);

       $result .= mb_substr ($data, 0, $poz).

               $ins_before.

               mb_substr ($data, $poz, $query_len).

               $ins_after;

       $data = mb_substr ($data, $poz+$query_len);

 }

 return $result;

}

?>



Enjoy!



[EDIT BY danbrown AT php DOT net: Reclassified to a more appropriate function manual page.]

projektas at gmail dot com 21-Oct-2008 08:29


First letter in upper case <hr />



<?php

header ('Content-type: text/html; charset=utf-8');



if (isset($_POST['check']) && !empty($_POST['check'])) {

    echo htmlspecialchars(ucfirst_utf8($_POST['check']));

} else {

    echo htmlspecialchars(ucfirst_utf8('Žąsinų'));

}



function ucfirst_utf8($str) {

    if (mb_check_encoding($str,'UTF-8')) {

        $first = mb_substr(

            mb_strtoupper($str, "utf-8"),0,1,'utf-8'

        );

        return $first.mb_substr(

            mb_strtolower($str,"utf-8"),1,mb_strlen($str),'utf-8'

        );

    } else {

        return $str;

    }

}

?>



<form method="post" action="" >

    <input type="input" name="check" />

    <input type="submit" />

</form>

Silvan 01-Sep-2007 05:30


Passing null as length will not make mb_substr use it's default, instead it will interpret it as 0.

<?php

mb_substr($str,$start,null,$encoding); //Returns '' (empty string) just like substr()

?>

Instead use:

<?php

mb_substr($str,$start,mb_strlen($str),$encoding);

?>

xiaogil at yahoo dot fr 02-Aug-2005 10:33


Thanks Darien from /freenode #php for the following example (a little bit changed).



It just prints the 6th character of $string.

You can replace the digits by the same in japanese, chinese or whatever language to make a test, it works perfect.



<?php

mb_internal_encoding("UTF-8");

$string = "0123456789";

$mystring = mb_substr($string,5,1);

echo $mystring;

?>



(I couldn't replace 0123456789 by chinese numbers for example here, because it's automatically converted into latin digits on this website, look : 

&#38646;&#19968;&#20108;&#19977;&#22235;

&#20116;&#20845;&#19971;&#20843;&#20061;)



gilv

drraf at tlen dot pl 23-Feb-2005 07:44


Note: If borders are out of string - mb_string() returns empty _string_, when function substr() returns _boolean_ false in this case.

Keep this in mind when using "===" comparisions.



Example code:

<?php



var_dump( substr( 'abc', 5, 2 ) ); // returns "false"

var_dump( mb_substr( 'abc', 5, 2 ) ); // returns ""



?>



It's especially confusing when using mbstring with function overloading turned on.

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