downloads | documentation | faq | getting help | mailing lists | licenses | wiki | reporting bugs | php.net sites | links | conferences | my php.net

search for in the

POSIX Regex> <preg_replace
Last updated: Fri, 13 Nov 2009

view this page in

preg_split

(PHP 4, PHP 5)

preg_split — Divide a string por uma expressão regular

Descrição

array preg_split ( string $pattern , string $subject [, int $limit [, int $flags ]] )

Divide uma dada string por uma expressão regular.

Parâmetros

pattern

O padrão a ser usado.

subject

A string de entrada.

limit

Se especificado, então somente limit pedaços da string serão retornados, e se limit for -1, significa "sem limite", que é útil quando especificando flags .

flags

flags pode ser uma combinação das seguintes flags (combinada com o operador | bit-a-bit):

PREG_SPLIT_NO_EMPTY
Se esta flag é usada, somente pedaços não vazios serão retornados pela preg_split().
PREG_SPLIT_DELIM_CAPTURE
Se esta flag é usada, expressão entre parênteses no padrão serão capturados e retornados também.
PREG_SPLIT_OFFSET_CAPTURE

Se esta flag é usada, para cada combinação o offset da string será também retornado. Note que isto modifica o valor de retorno em um array onde cada elemento é um array contendo a string combinada no índice 0 e o offset da mesma em subject no índice 1.

Valor Retornado

Retorna um array contendo pedaços de strings de subject divididos pelo que for combinado pelo pattern .

Histórico

Versão Descrição
4.3.0 A PREG_SPLIT_OFFSET_CAPTURE foi adicionada
4.0.5 A PREG_SPLIT_DELIM_CAPTURE foi adicionada
4.0.0 O parâmetro flags foi adicionado

Exemplos

Exemplo #1 Exemplo da preg_split(): Obtendo partes de uma string

<?php
// reparte a frase por algum número caracteres de vírgula ou espaço,
// incluindo " ", \r, \t, \n e \f
$keywords = preg_split("/[\s,]+/", "hypertext language, programming");
?>

Exemplo #2 Dividindo a string em cada caractere que a compõe

<?php
$str = 'string';
$chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY);
print_r($chars);
?>

Exemplo #3 Dividindo a string pela combinação e seus offsets

<?php
$str = 'hypertext language programming';
$chars = preg_split('/ /', $str, -1, PREG_SPLIT_OFFSET_CAPTURE);
print_r($chars);
?>

O exemplo acima irá imprimir:

Array
(
    [0] => Array
        (
            [0] => hypertext
            [1] => 0
        )

    [1] => Array
        (
            [0] => language
            [1] => 10
        )

    [2] => Array
        (
            [0] => programming
            [1] => 19
        )

)

Notas

Dica

Se você não precisa do poder das expressões regulares, pode optar por alternativa mais rápidas como explode() ou str_split().

Veja Também

  • spliti() - Separa strings em array utilizando expressões regulares insensíveis a maiúsculas e minúsculas
  • split() - Separa strings em array utilizando expressões regulares
  • implode() - Junta elementos de uma matriz em uma string
  • preg_match() - Perform a regular expression match
  • preg_match_all() - Perform a global regular expression match
  • preg_replace() - Perform a regular expression search and replace



POSIX Regex> <preg_replace
Last updated: Fri, 13 Nov 2009
 
add a note add a note User Contributed Notes
preg_split
jan dot sochor at icebolt dot info
24-Oct-2009 08:26
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 06:23
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 07:34
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 05:57
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 02:36
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 08:11
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 12:56
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 05:02
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 07:06
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 06:17
<?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 08:56
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 06:29
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 02:41
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 01:01
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 05:01
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.
add a note add a note

POSIX Regex> <preg_replace
Last updated: Fri, 13 Nov 2009
 
 
show source | credits | sitemap | contact | advertising | mirror sites