How to get the matched substring in preg_replace?

Question

I remove the first occurrence of a html tag in a string with preg_replace as

$html = preg_replace('#<p>(.*?)</p>#i', '', $html, 1);

How can I save the deleted substring as a new string:

$deleted = '<p>...</p>';

Answer 1

How about using preg_replace_callback which passes the match to a user defined function.

$str = preg_replace_callback($re, function ($m) use (&$p) { $p = $m[0]; }, $str, 1);

• $m any variable name for the matches array where index 0 is the full pattern match
• use (&$p) any variable name for storing the match (passed by reference).

See this demo at eval.in

Answer 2

to get the substring you can use preg_match():

preg_match('#<p>(.*?)</p>#i', $html, $matches);

just check the $matches variable it contain what you need.

If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches1 will have the text that matched the first captured parenthesized subpattern, and so on.

after that use preg_replace to delete the <p> tag.

but if you want only to remove the <p> tag and keep the substring just preg_replace like this :

$html = "left <p>substring</p> right";
$html = preg_replace('#</?p>#i', '', $html);

echo $html;

output :

left substring right

Answer 3

try using :

$result = preg_match('#<p>(.*?)</p>#i', $html);