preg_replace
PREG_SPLIT_OFFSET_CAPTURE should be maintained for UTF-8 characters, because it produces wrong results as if it is using strlen() internally, instead of using mb_strlen(), which is the right one...
preg_split
(PHP 4, PHP 5)
preg_split — 정규 표현식에 따라 문자열을 나눔
설명
array preg_split
( string $pattern
, string $subject
[, int $limit
[, int $flags
]] )
정규 표현식에 따라서 주어진 문자열을 나눕니다.
인수
- pattern
-
검색할 패턴 문자열.
- subject
-
입력 문자열.
- limit
-
지정하면, limit 회까지 나눠진 문자열을 반환하며, limit가 -1이면 "무제한"을 의미합니다. 이 값은 flags를 지정할 때 유용합니다.
- flags
-
flags는 다음 플래그들을 조합할 수 있습니다 (bitwise | 연산자로 조합합니다) :
- PREG_SPLIT_NO_EMPTY
- 이 플래그를 설정하면, preg_split()에 의해 나눈 후 비어있지 않은 조각만을 반환합니다.
- PREG_SPLIT_DELIM_CAPTURE
- 이 플래그를 설정하면, 구분자 패턴 안의 서브패턴도 검출하여 반환합니다.
- PREG_SPLIT_OFFSET_CAPTURE
-
이 플래그를 설정하면, 문자열의 시작 위치도 반환합니다. 반환값이 매치된 문자열을 오프셋 0으로, 문자열 시작 위치를 오프셋 1로 가지는 배열을 원소로 갖는 배열로 변하는 점에 주의하십시오.
반환값
pattern에 매치한 경계로 나눠진 subject의 부분을 가진 배열을 반환합니다.
변경점
| 버전 | 설명 |
|---|---|
| 4.3.0 | PREG_SPLIT_OFFSET_CAPTURE 추가 |
| 4.0.5 | PREG_SPLIT_DELIM_CAPTURE 추가 |
| 4.0.0 | flags 인수 추가 |
예제
Example #1 preg_split() 예제 : 검색 문자열의 일부만을 얻기
<?php
// " ", \r, \t, \n, \f를 포함하여
// 임의 갯수의 콤마와 스페이스로 구문을 나눕니다.
$keywords = preg_split("/[\s,]+/", "hypertext language, programming");
?>
Example #2 문자열을 구성 문자로 나누기.
<?php
$str = 'string';
$chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY);
print_r($chars);
?>
Example #3 매치와 시작위치로 문자열을 나누기.
<?php
$str = 'hypertext language programming';
$chars = preg_split('/ /', $str, -1, PREG_SPLIT_OFFSET_CAPTURE);
print_r($chars);
?>
위 예제의 출력:
Array
(
[0] => Array
(
[0] => hypertext
[1] => 0
)
[1] => Array
(
[0] => language
[1] => 10
)
[2] => Array
(
[0] => programming
[1] => 19
)
)
주의
Tip
정규 표현식의 힘이 필요하지 않으면, 더 빠른(그리고 간단한) explode()나 str_split()로 대체할 수 있습니다.
참고
- spliti() - Split string into array by regular expression case insensitive
- split() - Split string into array by regular expression
- implode() - 문자열로 배열 원소를 결합
- preg_match() - 정규표현식 매치를 수행
- preg_match_all() - 전역 정규 표현식 매치를 수행합니다
- preg_replace() - 정규 표현식 검색과 치환을 수행
add a note
User Contributed Notes
preg_split
w o z 2 2 a t y a h o o d o t c o m
23-Aug-2011 01:12
david dot binovec at gmail dot com
26-Jun-2011 04:08
Limit = 1 may be confusing. The important thing is that in case of limit equals to 1 will produce only ONE substring. Ergo the only one substring will be the first one as well as the last one. Tnat the rest of the string (after the first delimiter) will be placed to the last substring. But last is the first and only one.
<?php
$output = $preg_split('(/ /)', '1 2 3 4 5 6 7 8', 1);
echo $output[0] //will return whole string!;
$output = $preg_split('(/ /)', '1 2 3 4 5 6 7 8', 2);
echo $output[0] //will return 1;
echo $output[1] //will return '2 3 4 5 6 7 8';
?>
eric at clarinova dot com
25-Jun-2011 12:34
Here is another way to split a CamelCase string, which is a simpler expression than the one using lookaheads and lookbehinds:
preg_split('/([[:upper:]][[:lower:]]+)/', $last, null, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY)
It makes the entire CamelCased word the delimiter, then returns the delimiters (PREG_SPLIT_DELIM_CAPTURE) and omits the empty values between the delimiters (PREG_SPLIT_NO_EMPTY)
PhoneixSegovia at gmail dot com
26-Nov-2010 03:08
You must be caution when using lookbehind to a variable match.
For example:
'/(?<!\\\)\r?\n)/'
to match a new line when not \ is before it don't go as spected as it match \r as the lookbehind (becouse isn't a \) and is optional before \n.
You must use this for example:
'/((?<!\\\|\r)\n)|((?<!\\\)\r\n)/'
That match a alone \n (not preceded by \r or \) or a \r\n not preceded by a \.
Daniel Schroeder
03-Nov-2010 02:16
If you want to split by a char, but want to ignore that char in case it is escaped, use a lookbehind assertion.
In this example a string will be split by ":" but "\:" will be ignored:
<?php
$string='a:b:c\:d';
$array=preg_split('#(?<!\\\)\:#',$string);
print_r($array);
?>
Results into:
Array
(
[0] => a
[1] => b
[2] => c\:d
)
sergei dot garrison at gmail dot com
05-Mar-2010 06:34
If you need to split a list of "tags" while allowing for user error, you'll find this more useful than the manual's first example.
<?php
$string = 'one, two,three, four , five,six seven';
$array = preg_split("/[\s]*[,][\s]*/", $string);
print_r($array);
// Array ( [0] => one [1] => two [2] => three [3] => four [4] => five [5] => six seven )
?>
This splits the string *only* by commas, regardless of how many spaces there are on either side of any comma.
nesbert at gmail dot com
29-Jan-2010 02:16
Hope this helps someone...
<?php
/**
* Split a string into groups of words with a line no longer than $max
* characters.
*
* @param string $string
* @param integer $max
* @return array
**/
function split_words($string, $max = 1)
{
$words = preg_split('/\s/', $string);
$lines = array();
$line = '';
foreach ($words as $k => $word) {
$length = strlen($line . ' ' . $word);
if ($length <= $max) {
$line .= ' ' . $word;
} else if ($length > $max) {
if (!empty($line)) $lines[] = trim($line);
$line = $word;
} else {
$lines[] = trim($line) . ' ' . $word;
$line = '';
}
}
$lines[] = ($line = trim($line)) ? $line : $word;
return $lines;
}
?>
jan dot sochor at icebolt dot info
24-Oct-2009 01:56
Sometimes PREG_SPLIT_DELIM_CAPTURE does strange results.
<?php
$content = '<strong>Lorem ipsum dolor</strong> sit <img src="test.png" />amet <span class="test" style="color:red">consec<i>tet</i>uer</span>.';
$chars = preg_split('/<[^>]*[^\/]>/i', $content, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
print_r($chars);
?>
Produces:
Array
(
[0] => Lorem ipsum dolor
[1] => sit <img src="test.png" />amet
[2] => consec
[3] => tet
[4] => uer
)
So that the delimiter patterns are missing. If you wanna get these patters remember to use parentheses.
<?php
$chars = preg_split('/(<[^>]*[^\/]>)/i', $content, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
print_r($chars); //parentheses added
?>
Produces:
Array
(
[0] => <strong>
[1] => Lorem ipsum dolor
[2] => </strong>
[3] => sit <img src="test.png" />amet
[4] => <span class="test" style="color:red">
[5] => consec
[6] => <i>
[7] => tet
[8] => </i>
[9] => uer
[10] => </span>
[11] => .
)
php at dmi dot me dot uk
06-Oct-2009 11:53
To split a camel-cased string using preg_split() with lookaheads and lookbehinds:
<?php
function splitCamelCase($str) {
return preg_split('/(?<=\\w)(?=[A-Z])/', $str);
}
?>
Peter -the pete- de Pijd
24-Sep-2009 12:04
If you want to use something like explode(PHP_EOL, $string) but for all combinations of \r and \n, try this one:
<?php
$text = "A\nB\rC\r\nD\r\rE\n\nF";
$texts = preg_split("/((\r(?!\n))|((?<!\r)\n)|(\r\n))/", $text);
?>
result:
array("A", "B", "C", "D", "", "E", "", "F");
buzoganylaszlo at yahoo dot com
01-Aug-2009 10:27
Extending m.timmermans's solution, you can use the following code as a search expression parser:
<?php
$search_expression = "apple bear \"Tom Cruise\" or 'Mickey Mouse' another word";
$words = preg_split("/[\s,]*\\\"([^\\\"]+)\\\"[\s,]*|" . "[\s,]*'([^']+)'[\s,]*|" . "[\s,]+/", $search_expression, 0, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
print_r($words);
?>
The result will be:
Array
(
[0] => apple
[1] => bear
[2] => Tom Cruise
[3] => or
[4] => Mickey Mouse
[5] => another
[6] => word
)
1. Accepted delimiters: white spaces (space, tab, new line etc.) and commas.
2. You can use either simple (') or double (") quotes for expressions which contains more than one word.
wf
28-May-2009 07:06
Spacing out your CamelCase using preg_replace:
<?php
function spacify($camel, $glue = ' ') {
return preg_replace( '/([a-z0-9])([A-Z])/', "$1$glue$2", $camel );
}
echo spacify('CamelCaseWords'), "\n"; // 'Camel Case Words'
echo spacify('camelCaseWords'), "\n"; // 'camel Case Words'
?>
chris AT cmbuckley DOT co DOT uk
27-May-2009 12:41
Here's a helpful function to space out your CamelCase using preg_split:
<?php
function spacify($camel, $glue = ' ') {
return $camel[0] . substr(implode($glue, array_map('implode', array_chunk(preg_split('/([A-Z])/',
ucfirst($camel), -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE), 2))), 1);
}
echo spacify('CamelCaseWords'); // 'Camel Case Words'
echo spacify('camelCaseWords'); // 'camel Case Words'
?>
kenorb at gmail dot com
23-May-2009 05:26
If you need convert function arguments without default default values and references, you can try this code:
<?php
$func_args = '$node, $op, $a3 = NULL, $form = array(), $a4 = NULL'
$call_arg = preg_match_all('@(?<func_arg>\$[^,= ]+)@i', $func_args, $matches);
$call_arg = implode(',', $matches['func_arg']);
?>
Result: string = "$node,$op,$a3,$form,$a4"
bit_kahuna at yahoo dot com
27-Mar-2009 09:32
how to display a shortened text string with an elipsis, but on word boundaries only.
<?php
function truncate($string, $max = 70, $rep = '...') {
$words = preg_split("/[\s]+/", $string);
$newstring = '';
$numwords = 0;
foreach ($words as $word) {
if ((strlen($newstring) + 1 + strlen($word)) < $max) {
$newstring .= ' '.$word;
++$numwords;
} else {
break;
}
}
if ($numwords < count($words)) {
$newstring .= $rep;
}
return $newstring;
}
?>
hope this helps someone! thanks for all the help from everyone else!!
csaba at alum dot mit dot edu
17-Mar-2009 11:36
If the task is too complicated for preg_split, preg_match_all might come in handy, since preg_split is essentially a special case.
I wanted to split a string on a certain character (asterisk), but only if it wasn't escaped (by a preceding backslash). Thus, I should ensure an even number of backslashes before any asterisk meant as a splitter. Look-behind in a regular expression wouldn't work since the length of the preceding backslash sequence can't be fixed. So I turned to preg_match_all:
<?php
// split a string at unescaped asterisks
// where backslash is the escape character
$splitter = "/\\*((?:[^\\\\*]|\\\\.)*)/";
preg_match_all($splitter, "*$string", $aPieces, PREG_PATTERN_ORDER);
$aPieces = $aPieces[1];
// $aPieces now contains the exploded string
// and unescaping can be safely done on each piece
foreach ($aPieces as $idx=>$piece)
$aPieces[$idx] = preg_replace("/\\\\(.)/s", "$1", $piece);
?>
anajilly
17-Jul-2008 10:47
<?php
$s = '<p>bleh blah</p><p style="one">one two three</p>';
$htmlbits = preg_split('/(<p( style="[-:a-z0-9 ]+")?>|<\/p>)/i', $s, -1, PREG_SPLIT_DELIM_CAPTURE);
print_r($htmlbits);
?>
Array
(
[0] =>
[1] => <p>
[2] => bleh blah
[3] => </p>
[4] =>
[5] => <p style="one">
[6] => style="one"
[7] => one two three
[8] => </p>
[9] =>
)
two interesting bits:
1. When using PREG_SPLIT_DELIM_CAPTURE, if you use more than one pair of parentheses, the result array can have members representing all pairs. See array indexes 5 and 6 to see two adjacent delimiter results in which the second is a subset match of the first.
2. If a parenthesised sub-expression is made optional by a following question mark (ex: '/abc (optional subregex)?/') some split delimiters may be captured in the result while others are not. See array indexes 1 and 2 to see an instance where the overall match succeeded and returned a delimiter while the optional sub-expression '( style="[-:a-z0-9 ]+")?' did not match, and did not return a delimiter. This means it's possible to have a result with an unpredictable number of delimiters in the result array.
This second aspect is true irrespective of the number of pairs of parentheses in the regex. This means: in a regular expression with a single optional parenthesised sub-expression, the overall expression can match without generating a corresponding delimiter in the result.
m dot timmermans at home dot NOSPAM dot nl
29-May-2008 01:26
For people who want to use the double quote to group words/fields, kind of like CSV does, you can use the following expression:
<?php
$keywords = preg_split( "/[\s,]*\\\"([^\\\"]+)\\\"[\s,]*|[\s,]+/", "textline with, commas and \"quoted text\" inserted", 0, PREG_SPLIT_DELIM_CAPTURE );
?>
Which will result in:
Array
(
[0] => textline
[1] => with
[2] => commas
[3] => and
[4] => quoted text
[5] => inserted
)
crispytwo at yahoo dot com
04-Sep-2007 10:59
I was having trouble getting the PREG_SPLIT_DELIM_CAPTURE flag to work because I missed reading the "parenthesized expression" in the documentation :-(
So the pattern should look like:
/(A)/
not just
/A/
and it works as described/expected.
Steve
23-Mar-2005 07:11
preg_split() behaves differently from perl's split() if the string ends with a delimiter. This perl snippet will print 5:
my @a = split(/ /, "a b c d e ");
print scalar @a;
The corresponding php code prints 6:
<?php print count(preg_split("/ /", "a b c d e ")); ?>
This is not necessarily a bug (nowhere does the documentation say that preg_split() behaves the same as perl's split()) but it might surprise perl programmers.
jetsoft at iinet.net.au
25-Sep-2004 05:31
To clarify the "limit" parameter and the PREG_SPLIT_DELIM_CAPTURE option,
<?php
$preg_split('(/ /)', '1 2 3 4 5 6 7 8', 4 ,PREG_SPLIT_DELIM_CAPTURE );
?>
returns:
('1', ' ', '2', ' ' , '3', ' ', '4 5 6 7 8')
So you actually get 7 array items not 4
dave at codewhore dot org
29-May-2002 09:31
The above description for PREG_SPLIT_OFFSET_CAPTURE may be a bit confusing.
When the flag is or'd into the 'flags' parameter of preg_split, each match is returned in the form of a two-element array. For each of the two-element arrays, the first element is the matched string, while the second is the match's zero-based offset in the input string.
For example, if you called preg_split like this:
preg_split('/foo/', 'matchfoomatch', -1, PREG_SPLIT_OFFSET_CAPTURE);
it would return an array of the form:
Array(
[0] => Array([0] => "match", [1] => 0),
[1] => Array([1] => "match", [1] => 8)
)
Note that or'ing in PREG_DELIM_CAPTURE along with PREG_SPLIT_OFFSET_CAPTURE works as well.