Here's how to use grapheme_extract() to loop across a UTF-8 string character by character.
$str = "سabcक’…";
// if the previous line didn't come through, the string contained:
$n = 0;
for ( $start = 0, $next = 0, $maxbytes = strlen($str), $c = '';
$start < $maxbytes;
$c = grapheme_extract($str, 1, GRAPHEME_EXTR_MAXCHARS , ($start = $next), $next)
echo "This utf8 character is " . strlen($c) . " bytes long and its first byte is " . ord($c) . "\n";
echo "$n UTF-8 characters in a string of $maxbytes bytes!\n";
// Should print: 7 UTF8 characters in a string of 14 bytes!
(PHP 5 >= 5.3.0, PECL intl >= 1.0.0)
grapheme_extract — Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.
$start= 0 [, int
Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.
String to search.
Maximum number items - based on the $extract_type - to return.
Defines the type of units referred to by the $size parameter:
- GRAPHEME_EXTR_COUNT (default) - $size is the number of default grapheme clusters to extract.
- GRAPHEME_EXTR_MAXBYTES - $size is the maximum number of bytes returned.
- GRAPHEME_EXTR_MAXCHARS - $size is the maximum number of UTF-8 characters returned.
Starting position in $haystack in bytes - if given, it must be zero or a positive value that is less than or equal to the length of $haystack in bytes. If $start does not point to the first byte of a UTF-8 character, the start position is moved to the next character boundary.
Reference to a value that will be set to the next starting position. When the call returns, this may point to the first byte position past the end of the string.
A string starting at offset $start and ending on a default grapheme cluster boundary that conforms to the $size and $extract_type specified.
Example #1 grapheme_extract() example
$char_a_ring_nfd = "a\xCC\x8A"; // 'LATIN SMALL LETTER A WITH RING ABOVE' (U+00E5) normalization form "D"
$char_o_diaeresis_nfd = "o\xCC\x88"; // 'LATIN SMALL LETTER O WITH DIAERESIS' (U+00F6) normalization form "D"
print urlencode(grapheme_extract( $char_a_ring_nfd . $char_o_diaeresis_nfd, 1, GRAPHEME_EXTR_COUNT, 2));
The above example will output:
- grapheme_substr() - Return part of a string
- » Unicode Text Segmentation: Grapheme Cluster Boundaries