mb_strlen
Compat function to mimic mb_strlen().
Description
Returns (int)
String length of `$str`.
Parameters (2)
- 0. $str (string)
- The string to retrieve the character length from.
- 1. $encoding — Optional. (null) =>
null
- Character encoding to use. Default null.
Usage
if ( !function_exists( 'mb_strlen' ) ) { require_once ABSPATH . WPINC . '/compat.php'; } // The string to retrieve the character length from. $str = ''; // Optional. Character encoding to use. Default null. $encoding = null; // NOTICE! Understand what this does before running. $result = mb_strlen($str, $encoding);
Defined (2)
The function is defined in the following location(s).
- /wp-includes/compat.php
- function mb_strlen( $str, $encoding = null ) {
- return _mb_strlen( $str, $encoding );
- }
- function _mb_strlen( $str, $encoding = null ) {
- if ( null === $encoding ) {
- $encoding = get_option( 'blog_charset' );
- }
- /**
- * The solution below works only for UTF-8, so in case of a different charset
- * just use built-in strlen().
- */
- if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
- return strlen( $str );
- }
- if ( _wp_can_use_pcre_u() ) {
- // Use the regex unicode support to separate the UTF-8 characters into an array.
- preg_match_all( '/./us', $str, $match );
- return count( $match[0] );
- }
- $regex = '/(?:
- [\x00-\x7F] # single-byte sequences 0xxxxxxx
- | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx
- | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2
- | [\xE1-\xEC][\x80-\xBF]{2}
- | \xED[\x80-\x9F][\x80-\xBF]
- | [\xEE-\xEF][\x80-\xBF]{2}
- | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3
- | [\xF1-\xF3][\x80-\xBF]{3}
- | \xF4[\x80-\x8F][\x80-\xBF]{2}
- )/x';
- // Start at 1 instead of 0 since the first thing we do is decrement.
- $count = 1;
- do {
- // We had some string left over from the last round, but we counted it in that last round.
- $count--;
- /**
- * Split by UTF-8 character, limit to 1000 characters (last array element will contain
- * the rest of the string).
- */
- $pieces = preg_split( $regex, $str, 1000 );
- // Increment.
- $count += count( $pieces );
- // If there's anything left over, repeat the loop.
- } while ( $str = array_pop( $pieces ) );
- // Fencepost: preg_split() always returns one extra item in the array.
- return --$count;
- }