grapheme_substr

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

grapheme_substr — Return part of a string

说明

过程化风格

int grapheme_substr ( string $string , int $start [, int $length ] )

Return part of a string

参数

string: The input string. Must be valid UTF-8.
start: 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, FALSE will be returned.

返回值

Returns the extracted part of $string.

更新日志

版本	说明
5.4	If `length` is given and positive and the argument string is shorter than the specified length, all the rest of the string according to `start` parameter is returned. Previously, `FALSE` was returned.

范例

Example #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