Multibyte String 函数
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mb_strpos

(PHP 4 >= 4.0.6, PHP 5)

mb_strpos — Find position of first occurrence of string in a string

说明

int mb_strpos ( string $haystack , string $needle [, int $offset = 0 [, 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.

参数

haystack

The string being checked.

needle

The string to find in haystack. In contrast with strpos(), numeric values are not applied as the ordinal value of a character.

offset

The search offset. If it is not specified, 0 is used.

encoding

encoding 参数为字符编码。如果省略，则使用内部字符编码。

返回值

Returns the numeric position of the first occurrence of needle in the haystack string. If needle is not found, it returns FALSE.

参见

Multibyte String 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: Find position of first occurrence of string in a string

用户评论:

brendel at krumedia dot de (11-Mar-2008 12:42)

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

zangaru at hotmail dot com (06-Jul-2007 06:42)

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 01:12)

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 05:42)

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 05:39)

It appears that the $offset value is a character count not a byte count.  (This may seem obvious but it isn't explicitly stated)