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preg_replace_callback_array

(PHP 7, PHP 8)

preg_replace_callback_arrayRealiza una búsqueda de coincidencia con una expresión regular y reemplaza mediante una función de devolución de llamada

Descripción

preg_replace_callback_array(
    array $pattern,
    string|array $subject,
    int $limit = -1,
    int &$count = null,
    int $flags = 0
): string|array|null

El comportamiento de esta función es similar a preg_replace_callback(), con la excepción de que las funciones de devolución de llamada se ejecutan para cada patrón.

Parámetros

pattern

Un array asociativo que establece una relación entre los patrones (claves) y las funciones de devolución de llamada callable (valores).

subject

La chaîne de caractères o tableau que contiene los chaîne de caractères a buscar y reemplazar.

limit

El número máximo de reemplazos para cada patrón en cada chaîne de caractères subject. Por omisión -1 (sin límite).

count

Si se proporciona, esta variable será rellenada con el número de reemplazos realizados.

flags

flags puede ser una combinación de los indicadores PREG_OFFSET_CAPTURE y PREG_UNMATCHED_AS_NULL, que influyen en el formato del array de coincidencias. Ver la descripción de preg_match() para más detalles.

Valores devueltos

preg_replace_callback_array() devuelve un array si el parámetro subject es un array, o de lo contrario una chaîne de caractères. En caso de error, el valor devuelto es null.

Si se encuentran coincidencias, el nuevo sujeto será devuelto, de lo contrario subject será devuelto sin cambios.

Errores/Excepciones

If the regex pattern passed does not compile to a valid regex, an E_WARNING is emitted.

Historial de cambios

Versión Descripción
7.4.0 El parámetro flags ha sido añadido.

Ejemplos

Ejemplo #1 Ejemplo de preg_replace_callback_array()

<?php
$subject
= 'Aaaaaa Bbb';

preg_replace_callback_array(
[
'~[a]+~i' => function ($match) {
echo
strlen($match[0]), ' coincidencias de "a" encontradas', PHP_EOL;
},
'~[b]+~i' => function ($match) {
echo
strlen($match[0]), ' coincidencias de "b" encontradas', PHP_EOL;
}
],
$subject
);
?>

El resultado del ejemplo sería:

6 coincidencias de "a" encontradas
3 coincidencias de "b" encontradas

Ver también

add a note

User Contributed Notes 4 notes

up
10
Sz.
7 years ago
Based on some tests, I found these important traits of the function. (These would
be nice to see documented as part of its spec, e.g. for confirmation. Without that,
this is just experimental curiosity. Still better than guesswork, though! ;) )

1. Changes cascade over a subject across callbacks, i.e. a change made to a
subject by a callback will be seen by the next callback, if its pattern matches
the changed subject.
(But a change made by a previous call of the *same* callback (on any subject)
will not be seen by that callback again.)

2. The pattern + callback pairs will be applied in the order of their appearance
in $patterns_and_callbacks.

3. The callback can't be null (or '') for a quick shortcut for empty replacements.

4. Overall, the algorithm starts iterating over $patterns_and_callbacks, and then
feeds each $subject to the current callback, repeatedly for every single match
of its pattern on the current subject (unlike "preg_match_all", that is, which
can do the same in one go, returning the accumulated results in an array).

This basically means that the "crown jewel", an even more efficient function:
"preg_replace_all_callback_array" is still missing from the collection.

(Of course, that would better fit a new design of the regex API, where one
API could flexibly handle various different modes via some $flags = [] array.)

5. (This last one is not specific to this function, but inherent to regexes, OTOH,
it's probably more relevant here than anywhere else in PHP's regex support.)

Even apparently simple cases can generate a crazy (and difficult-to-predict)
number of matches, and therefore callback invokations, so remember the set
$limit, where affordable. But, of course, try to sharpen your patterns first!

E.g. use ^...$ anchoring to avoid unintended extra calls on matching substrings
of a subject, (I.e. '/.*/', without anchoring, would match twice: once for the
whole subject, and then for a trailing empty substring -- but I'm not quite sure
this should actually be correct behavior, though.)
up
9
drevilkuko at gmail dot com
9 years ago
finally!!!

before (<=php5.6):

<?php
$htmlString
= preg_replace_callback(
'/(href="?)(\S+)("?)/i',
function (&
$matches) {
return
$matches[1] . urldecode($matches[2]) . $matches[3];
},
$htmlString
);

$htmlString = preg_replace_callback(
'/(href="?\S+)(%24)(\S+)?"?/i', // %24 = $
function (&$matches) {
return
urldecode($matches[1] . '$' . $matches[3]);
},
$htmlString
);
?>

php7

<?php

$htmlString
= preg_replace_callback_array(
[
'/(href="?)(\S+)("?)/i' => function (&$matches) {
return
$matches[1] . urldecode($matches[2]) . $matches[3];
},
'/(href="?\S+)(%24)(\S+)?"?/i' => function (&$matches) {
return
urldecode($matches[1] . '$' . $matches[3]);
}
],
$htmlString
);
?>
up
1
claus at tondering dot dk
1 year ago
Note that the first replacement is applied to the whole string before the next replacement is applied.

For example:

<?php
$subject
= 'a b a b a b';

preg_replace_callback_array(
[
'/a/' => function ($match) {
echo
'"a" found', PHP_EOL;
},
'/b/' => function ($match) {
echo
'"b" found', PHP_EOL;
}
],
$subject
);

?>

will print

"a" found
"a" found
"a" found
"b" found
"b" found
"b" found

This means that you cannot use global variables to communicate information between the functions about what point in the string you have reached.
up
-3
jfcherng at NOSPAM dot gmail dot com
9 years ago
Here's a possible alternative in older PHP.

<?php

// if (!function_exists('preg_replace_callback_array')) {

function preg_replace_callback_array (array $patterns_and_callbacks, $subject, $limit=-1, &$count=NULL) {
$count = 0;
foreach (
$patterns_and_callbacks as $pattern => &$callback) {
$subject = preg_replace_callback($pattern, $callback, $subject, $limit, $partial_count);
$count += $partial_count;
}
return
preg_last_error() == PREG_NO_ERROR ? $subject : NULL;
}

// }

?>
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