- PHP 手册
- 函数参考
- 国际化与字符编码支持
- intl
- Grapheme 函数
grapheme_substr
(PHP 5 >= 5.3.0, PHP 7, PHP 8, PECL intl >= 1.0.0)
grapheme_substr — Return part of a string
说明
过程化风格
grapheme_substr(string$string, int $offset, ?int $length = null): string|false
Return part of a string
参数
-
string -
The input string. Must be valid UTF-8.
-
offset -
Start position in default grapheme units. If $start is non-negative, the returned string will start at the $start'th position in $string, counting from zero. If $start is negative, the returned string will start at the $start'th grapheme unit from the end of string.
-
length -
Length in grapheme units. If $length is given and is positive, the string returned will contain at most $length grapheme units beginning from $start (depending on the length of string). If $length is given and is negative, then that many grapheme units will be omitted from the end of string (after the start position has been calculated when a start is negative). If $start denotes a position beyond this truncation,
falsewill be returned.
返回值
Returns the extracted part of string, 或者在失败时返回 false.
范例
示例 #1 grapheme_substr() 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_substr( "ao" . $char_a_ring_nfd . "bc" . $char_o_diaeresis_nfd . "O", 2, -1 ));
?>
以上例程会输出：
a%CC%8Abco%CC%88
参见
- grapheme_extract() - Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8
- » Unicode Text Segmentation: Grapheme Cluster Boundaries
User Contributed Notes
There are no user contributed notes for this page.官方地址：https://www.php.net/manual/en/function.grapheme-substr.php