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iconv_strlen

(PHP 5, PHP 7, PHP 8)

iconv_strlenRetourne le nombre de caractères d'une chaîne

Description

iconv_strlen(string $string, ?string $encoding = null): int|false

À l'opposée de strlen(), la valeur de retour de iconv_strlen() est le nombre de caractères faisant partie de la séquence d'octets string, ce qui n'est pas toujours la même chose que la taille en octets de la chaîne de caractères.

Liste de paramètres

string

La chaîne de caractères.

encoding

Si encoding est omit ou null, string est supposée être encodée en iconv.internal_encoding.

Valeurs de retour

Retourne le nombre de caractères de la chaîne string, sous la forme d'un entier, ou false si une erreur se produit durant l'encodage.

Historique

Version Description
8.0.0 encoding est désormais nullable.

Voir aussi

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User Contributed Notes 2 notes

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12
hfuecks @ nospam org
18 years ago
If iconv_strlen is passed a UTF-8 string containing badly formed sequences, it will return FALSE. This is in contrast to mb_strlen of the behaviour of utf8_decode, which strip out any bad sequences;

<?php
# UTF-8 string containing bad sequence: \xe9
$str = "I?t?rn?ti?n\xe9?liz?ti?n";

print
"mb_strlen: ".mb_strlen($str,'UTF-8')."\n";
print
"strlen/utf8_decode: ".strlen(utf8_decode($str))."\n";
print
"iconv_strlen: ".iconv_strlen($str,'UTF-8')."\n";
?>

Displays;

mb_strlen: 20
strlen/utf8_decode: 20
iconv_strlen:

(PHP 5.0.5)

As such it is being "stricter" than mb_strlen and it may mean you need to check for invalid sequences first. A quick way to check is to exploit the behaviour of the PCRE extension (see notes on pattern modifiers);

<?php
if (preg_match('/^.{1}/us',$str,$ar) != 1) {
die(
"string contains invalid UTF-8");
}
?>

A slower but stricter check (regex) can be found at: http://www.w3.org/International/questions/qa-forms-utf-8

Similiar applies to iconv_substr, iconv_strpos and iconv_strrpos
up
4
sheryl
3 years ago
Notice there is a disconnect:
>If charset`parameter is omitted, str is assumed to be encoded in iconv.internal_encoding.

But clicking on the iconv.internal_encoding link (https://www.php.net/manual/en/iconv.configuration.php), the docs indicate that iconv.internal_encoding is deprecated since 5.6.
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