mb_strlen
mb_strpos() used in a loop on a long string may become very slow even if you provide the $offset. Unlike strpos(), mb_strpos() has to skip the number of characters
every call specified by $offset to get the real byte position used internally. (Whereas strpos can just add the offset.)
If your encoding is UTF-8 and you try to find only single characters with ordinal <= 127 you may still use strpos(), substr(), ... This works cause every byte of a UTF-8 sequence is >= 128.
Greetz maz
mb_strpos
(PHP 4 >= 4.0.6, PHP 5)
mb_strpos — Find position of first occurrence of string in a string
Beschreibung
int mb_strpos
( string $haystack
, string $needle
[, int $offset
[, string $encoding
]] )
Finds position of the first occurrence of a string in a string.
Performs a multi-byte safe strpos() operation based on number of characters. The first character's position is 0, the second character position is 1, and so on.
Parameter-Liste
- haystack
-
The string being checked.
- needle
-
The position counted from the beginning of haystack .
- offset
-
The search offset. If it is not specified, 0 is used.
- encoding
-
Der encoding Parameter legt das Zeichenencoding fest. Wird er nicht übergeben so wird das interne Zeichenencoding genutzt.
Rückgabewerte
Returns the numeric position of the first occurrence of needle in the haystack string. If needle is not found, it returns FALSE.
Siehe auch
- mb_internal_encoding() - Set/Get internal character encoding
- strpos() - Sucht das erste Vorkommen des Suchstrings
add a note
User Contributed Notesmb_strpos
brendel at krumedia dot de
11-Mar-2008 12:42
11-Mar-2008 12:42
zangaru at hotmail dot com
06-Jul-2007 05:42
06-Jul-2007 05:42
Hello,
Just replaced strpos() with mb_strpos() and now I am getting following error:
PHP Warning: mb_strpos() [<a href='function.mb-strpos'>function.mb-strpos</a>]: Empty delimiter
PHP version: 5.2.3
OS: Win XP Prof
Web Server: IIS
I checked your bugs and mentioned that mb_string functions have been fixed as of 5.2.0 but it does not seem to be the case (Bug #39400).
My code:
==============================================
$charOut = mb_substr($tmpStr, $tmpKey[0], 1);
$posOut = mb_strpos($charList, $charOut);
if ($posOut !== FALSE) {
// do something here
}
==============================================
stestagg at talk21 dot com
06-Aug-2006 12:12
06-Aug-2006 12:12
sorry, my previous post had an error. replace the 1000 with strlen($haystack) to handle strings longer than 1000 chars.
btw. This is an issue with the mbstring functions. you can't specify the $encoding without specifying a $length, thus this reduces the functionality of mb_substr compared to substr
stestagg at talk21 dot com
04-Aug-2006 04:42
04-Aug-2006 04:42
a sample mb_str_replace function:
function mb_str_replace($haystack, $search,$replace, $offset=0,$encoding='auto'){
$len_sch=mb_strlen($search,$encoding);
$len_rep=mb_strlen($replace,$encoding);
while (($offset=mb_strpos($haystack,$search,$offset,$encoding))!==false){
$haystack=mb_substr($haystack,0,$offset,$encoding)
.$replace
.mb_substr($haystack,$offset+$len_sch,1000,$encoding);
$offset=$offset+$len_rep;
if ($offset>mb_strlen($haystack,$encoding))break;
}
return $haystack;
}
stestagg at talk21 dot com
04-Aug-2006 04:39
04-Aug-2006 04:39
It appears that the $offset value is a character count not a byte count. (This may seem obvious but it isn't explicitly stated)