grapheme_extract
(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
說明
過程化風格
string
$haystack
,int
$size
,int
$type
= GRAPHEME_EXTR_COUNT
,int
$offset
= 0,int
&$next
= null
): string|false
Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.
參數
-
haystack
-
String to search.
-
size
-
Maximum number items - based on the
type
- to return. -
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.
- GRAPHEME_EXTR_COUNT (default) -
-
offset
-
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 ofhaystack
in bytes, or a negative value that counts from the end ofhaystack
. Ifoffset
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.
返回值
A string starting at offset offset
and ending on a default grapheme cluster
boundary that conforms to the size
and type
specified,
或者在失敗時返回 false
.
更新日誌
版本 | 說明 |
---|---|
7.1.0 |
Support for negative offset s has been added.
|
範例
示例 #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));
?>
以上例程會輸出:
o%CC%88
參見
- grapheme_substr() - Return part of a string
- » Unicode Text Segmentation: Grapheme Cluster Boundaries