grapheme_extract

(PHP 5 >= 5.3.0, PECL intl >= 1.0.0)

grapheme_extractFunction to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.

Descrizione

Stile procedurale

string grapheme_extract ( string $haystack , int $size [, int $extract_type [, int $start = 0 [, int &$next ]]] )

Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.

Elenco dei parametri

haystack

String to search.

size

Maximum number items - based on the $extract_type - to return.

extract_type

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.

start

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.

next

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.

Valori restituiti

A string starting at offset $start and ending on a default grapheme cluster boundary that conforms to the $size and $extract_type specified.

Esempi

Example #1 grapheme_extract() example

<?php

$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_nfd1GRAPHEME_EXTR_COUNT2));

?>

Il precedente esempio visualizzerà:

o%CC%88
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User Contributed Notes 1 note

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AJH
3 years ago
Here's how to use grapheme_extract() to loop across a UTF-8 string character by character.

<?php

$str
= "سabcक’…";
// if the previous line didn't come through, the string contained:
//U+0633,U+0061,U+0062,U+0063,U+0915,U+2019,U+2026

$n = 0;

for (   
$start = 0, $next = 0, $maxbytes = strlen($str), $c = '';
       
$start < $maxbytes;
       
$c = grapheme_extract($str, 1, GRAPHEME_EXTR_MAXCHARS , ($start = $next), $next)
    )
{
    if (empty(
$c))
        continue;
    echo
"This utf8 character is " . strlen($c) . " bytes long and its first byte is " . ord($c[0]) . "\n";
   
$n++;
}
echo
"$n UTF-8 characters in a string of $maxbytes bytes!\n";
// Should print: 7 UTF8 characters in a string of 14 bytes!
?>
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