Named backreferences with preg_replace

backreference, php, preg-replace, regex

Solution

They exist:

http://www.php.net/manual/en/regexp.reference.back-references.php

With preg_replace_callback:

function my_replace($matches) {
    return '/user/profile/' . $matches['id'];
}
$newandimproved = preg_replace_callback('#^user/(?P<id>[^/]+)$#Di', 'my_replace', $string);

Or even quicker

$newandimproved = preg_replace('#^user/([^/]+)$#Di', '/user/profile/$1', $string);

Problem

Pretty straightforward; I can't seem to find anything definitive regarding PHP's `preg_replace()` supporting named backreferences: ``` // should match, replace, and output: user/profile/foo $string = 'user/foo'; echo preg_replace('#^user/(?P<id>[^/]+)$#Di', 'user/profile/(?P=id)', $string); ``` This is a trivial example, but I'm wondering if this syntax, `(?P=name)` is simply not supported. Syntactical issue, or non-existent functionality?

Original source