PHP preg_match() doesn't match all subpatterns - php

Question

I have a preg_match() which matches the pattern but doesn't receive the expected matches (in third param).
My regex patterns have multiple subpatterns.
$pattern = "~^&multi&[^&]+(&(?:(p-(?<sad>[1-9]\d*)|page-(?<sad>[1-9]\d*))))?&[^&]+(&(?:(p-(?<gogosi>[1-9]\d*)|page-(?<gogosi>[1-9]\d*))))?&?$~J";
$string = "&multi&mickael&p-23&george&page-34";
preg_match($pattern, $string, $matches);
This is what $matches contains:
Array
(
[0] => &multi&mickael&p-23&george&page-34
[1] => &p-23
[2] => p-23
[sad] =>
[3] => 23
[4] =>
[5] => &page-34
[6] => page-34
[gogosi] => 34
[7] =>
[8] => 34
)
The problem is [sad] should have 23 value.
If I don't include in $string second page (page-34), 'cause is optional [...]
$string = "&multi&mickael&p-23&george";
[...] I have good $matches 'cause my [sad] got his value:
Array
(
[0] => &multi&mickael&p-23&george
[1] => &p-23
[2] => p-23
[sad] => 23
[3] => 23
)
But I want regex to return properly value even when I have both paginations in $string.
What to do such that all subpatterns will have their value ?
Note: Words as ('p', 'page') are only examples. Can be any words there.
Note: Above data is just an example. Don't give me workaround solutions, but something good for any input data.

Answer 1

You may use a branch reset group, (?|...|...):
'~^&multi&[^&]+(&((?|p-(?<sad>[1-9]\d*)|page-(?<sad>[1-9]\d*))))?&[^&]+(&((?|p-(?<gogosi>[1-9]\d*)|page-(?<gogosi>[1-9]\d*))))?&?$~J'
See the regex demo.
See the PHP demo:
$pattern = "~^&multi&[^&]+(&((?|p-(?<sad>[1-9]\d*)|page-(?<sad>[1-9]\d*))))?&[^&]+(&((?|p-(?<gogosi>[1-9]\d*)|page-(?<gogosi>[1-9]\d*))))?&?$~J";
$string = "&multi&mickael&p-23&george&page-34";
if (preg_match($pattern, $string, $matches)) {
print_r($matches);
}
Output:
Array
(
[0] => &multi&mickael&p-23&george&page-34
[1] => &p-23
[2] => p-23
[sad] => 23
[3] => 23
[4] => &page-34
[5] => page-34
[gogosi] => 34
[6] => 34
)