Preg_replace, point after and before selection - php

Question

<div style="display:none">250</div>.<div style="display:none">145</div>
id want:
<div style="display:none">250</div>#.#<div style="display:none">145</div>
or like this:
<div style="display:none">111</div>125<div style="display:none">110</div>
where id want
<div style="display:none">111</div>#125#<div style="display:none">110</div>
id like a preg replace to put those hashtags around the numb, so i asume the REGEX would look something like this:
"<\/div>[.]|<\/div>\d{1,3}"
The digit (in case its a digit, can be 1-3 digits), or it can be a dot.
Anyhow, i dont know hot to preg replace around the value:
"<\/div>[.]|<\/div>\d{1,3}" replace: $0#
Inserts it after the value..
EDIT
I cannot use a HTML parser, because i cannot find one that does not threat styles / classes as plaintext, and i need the values attached, to determine if the element is visible or not :(
and yes, it is driving me insane, but i am almost done :)

Answer 1

You really should not be trying to parse HTML with regex. There are only a couple of people I know who can do it. And even if you would have been one of them regex still is not the right tool for the job. Use PHP's DOMDocument optionally with DOMXPath.
With xpath:
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$textNode = $xpath->query('//text()')->item(1);
$textNode->parentNode->replaceChild($dom->createTextNode('#' . $textNode->textContent . '#'), $textNode);
echo htmlspecialchars($dom->saveHTML());
http://codepad.viper-7.com/KLTLDA
With childnodes:
$dom = new DOMDocument();
$dom->loadHTML($html);
$body = $dom->getElementsByTagName('body')->item(0);
$textNode = $body->childNodes->item(1);
$textNode->parentNode->replaceChild($dom->createTextNode('#' . $textNode->textContent . '#'), $textNode);
echo htmlspecialchars($dom->saveHTML());
http://codepad.viper-7.com/Ii4vPb

Answer 2

In your case,
preg_replace("~</div\s*>(\.|\d{1,3})<div~i", '</div>#$1#<div', $string);
That's assuming no spaces between the divs and the content, and nothing otherwise weird is between.
Note that regex is very brittle, and would fail silently on even the slightest change in HTML.