Php/docs/function.grapheme-substr

• PHP Manual
• Grapheme 函数
• Return part of a string

grapheme_substr

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0)

grapheme_substr — Return part of a string

说明

过程化风格

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

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.

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