Php/docs/function.grapheme-extract
grapheme_extract
(PHP 5 >= 5.3.0, PHP 7, 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
说明
过程化风格
grapheme_extract
( string $haystack
, int $size
[, int $extract_type
[, int $start = 0
[, int &$next
]]] ) : string
Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.
参数
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, or a negative value that counts from the end of $haystack. 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.
返回值
A string starting at offset $start and ending on a default grapheme cluster boundary that conforms to the $size and $extract_type specified.
更新日志
| 版本 | 说明 |
|---|---|
| 7.1.0 | Support for negative starts has been added.
|
范例
Example #1 grapheme_extract() example
<?php$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));?>
以上例程会输出：
o%CC%88
参见
- grapheme_substr() - Return part of a string
- » Unicode Text Segmentation: Grapheme Cluster Boundaries
