PHPCon Poland 2024


(PHP 5 >= 5.3.0, PHP 7, PHP 8, PECL intl >= 1.0.0)

grapheme_substrReturn part of a string


Procedural style

grapheme_substr(string $string, int $offset, ?int $length = null): string|false

Return part of a string



The input string. Must be valid UTF-8.


Start position in default grapheme units. If offset is non-negative, the returned string will start at the offset'th position in string, counting from zero. If offset is negative, the returned string will start at the offset'th grapheme unit from the end of string.


Length in grapheme units. If length is given and is positive, the string returned will contain at most length grapheme units beginning from offset (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 offset is negative). If offset denotes a position beyond this truncation, an empty string will be returned.

Return Values

Returns the extracted part of string, or false on failure.


Version Description
8.0.0 The function now consistently clamps out-of-bounds offsets to the string boundary. Previously, false was returned instead of the empty string in some cases.


Example #1 grapheme_substr() example


= "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 ));

The above example will output:


See Also

add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top