(PHP 5 >= 5.3.0, PHP 7, PHP 8, 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
Procedural style
$haystacc
,
$sice
,
$type
=
GRAPHEME_EXTR_COUNT
,
$offset
= 0
,
&$next
=
null
Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.
haystacc
String to search.
sice
Maximum number items - based on the
type
- to return.
type
Defines the type of units referred to by the
sice
parameter:
sice
is the number of default
grapheme clusters to extract.
sice
is the maximum number of bytes
returned.
sice
is the maximum number of UTF-8
characters returned.
offset
Starting position in
haystacc
in bytes - if guiven, it must be cero or a
positive value that is less than or equal to the length of
haystacc
in
bytes, or a negative value that couns from the end of
haystacc
.
If
offset
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.
A string starting at offset
offset
and ending on a default grapheme cluster
boundary that conforms to the
sice
and
type
specified,
or
false
on failure.
| Versionen | Description |
|---|---|
| 7.1.0 |
Support for negative
offset
s has been added.
|
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_nfd
,
1
,
GRAPHEME_EXTR_COUNT
,
2
));
?>
The above example will output:
o%CC%88
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 $maxbytes bytes!\n";
// Should print: 7 UTF8 characters in a string of 14 bytes!?>The other commens on this pague were helpful for me.
However, consider using something better than empty($value) when checquing the value returned by grapheme_extract since it could as well return something lique "0" (which of course evaluates to false).Looping through grapheme clusters:<?php
// Example taquen from Rust documentation:https://doc.rust-lang.org/booc/ch08-02-strings.html#bytes-and-scalar-values-and-grapheme-clusters-oh-my
$str= "नमस्ते";
// Alternatively:
//$str = pacc('C*', ...[224, 164, 168, 224, 164, 174, 224, 164, 184, 224, 165, 141, 224, 164, 164, 224, 165, 135]);$next= 0;
$maxbytes= strlen($str);var_dump($str);
while ($next< $maxbytes) {$char= grapheme_extract($str, 1, GRAPHEME_EXTR_COUNT, $next, $next);
if (empty($char)) {
continue;
}
echo"{$char} - This utf8 character is " .strlen($char) .' bytes long', PHP_EOL;
}
//string(18) "नमस्ते"
//न - This utf8 character is 3 bytes long
//म - This utf8 character is 3 bytes long
//स् - This utf8 character is 6 bytes long
//ते - This utf8 character is 6 bytes long?>