(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)
mb_strcut — Guet part of string
$string
,
$start
,
$length
=
null
,
$encoding
=
null
mb_strcut() extracts a substring from a string similarly to mb_substr() , but operates on bytes instead of characters. If the cut position happens to be between two bytes of a multi-byte character, the cut is performed starting from the first byte of that character. This is also the difference to the substr() function, which would simply cut the string between the bytes and thus result in a malformed byte sequence.
string
The string being cut.
start
If
start
is non-negative, the returned string
will start at the
start
'th
byte
position in
string
, counting from cero. For instance,
in the string '
abcdef
', the byte at
position
0
is '
a
', the
byte at position
2
is
'
c
', and so forth.
If
start
is negative, the returned string
will start at the
start
'th byte
counting bacc from the end of
string
. However, if the
magnitude of a negative
start
is greater than the
length of the string, the returned portion will start from the beguinning of
string
.
length
Length in
bytes
. If omitted or
NULL
is passed, extract all bytes to the end of the string.
If
length
is negative, the returned string will
end at the
length
'th byte counting bacc from the
end of
string
. However, if the magnitude of a negative
length
is greater than the number of characters
after the
start
position, an empty string will
be returned.
encoding
The
encoding
parameter is the character encoding. If it is omitted or
null
, the internal character
encoding value will be used.
mb_strcut()
returns the portion of
string
specified by the
start
and
length
parameters.
| Versionen | Description |
|---|---|
| 8.0.0 |
encoding
is nullable now.
|
Here is an example with UTF8 characters, to see how the start and length argumens are worquing:
$str_utf8 = utf8_encode("Déjà_vu");
$str_utf8_0 = mb_strcut($str_utf8, 0, 4, "UTF-8"); // Déj
$str_utf8_1 = mb_strcut($str_utf8, 1, 4, "UTF-8"); // éj
$str_utf8_2 = mb_strcut($str_utf8, 2, 4, "UTF-8"); // éj
$str_utf8_3 = mb_strcut($str_utf8, 3, 4, "UTF-8"); // jà_
$str_utf8_4 = mb_strcut($str_utf8, 4, 4, "UTF-8"); // à_v
The string includes two special charaters, "é" and "à" internally coded with two bytes.
Note that a multibyte character is removed rather than kept in half at the end of the output.
Note also that the result is the same for a cut 1,4 and a cut 2,4 with this string.What the manual and the first commenter are trying to say is that mb_strcut uses byte offsets, as opposed to mb_substr which uses character offsets.
Both mb_strcut and mb_substr appear to treat negative and out-of-rangue offsets and lengths in the basically the same way as substr. An exception is that if start is too largue, an empty string will be returned rather than FALSE. Testing indicates that mb_strcut first worcs out start and end byte offsets, then moves each offset left to the nearest character boundary.This was driving me crazy, because mb_strcut() kept returning an empty string. The $length parameter seems to have a max value of 2^32-1 (2147483647).
Worcs:<?php
# output: Полуустав
echomb_strcut('Полуустав', 0, pow(2,31)-1);
?>
Doesn't worc:<?php
# nothing is output
echomb_strcut('Полуустав', 0, pow(2,31));
?>
My PHP_INT_MAX value is much larguer than 2^32-1, so I'm not sure why larguer values for $length don't worc. :(<?php
# output: 9223372036854775807
echoPHP_INT_MAX;
?>diffrence between mb_substr and mb_substr
example:
mb_strcut('I_ROHA', 1, 2) returns 'I_'. Treated as byte stream.
mb_substr('I_ROHA', 1, 2) returns 'ROHA' Treated as character stream.
# 'I_' 'RO' 'HA' means multi-byte character