<?php
$data = "<p class=\"title\">Title one</p>";
$data .= "<p class=\"title\">Title two</p>";
$data .= "<p class=\"title\">Title three</p>";
$reg = "/<p.*?class=[\"']*title[\"']*.*?>.*?<\/p.*?>/si";
$repl = "<p class=\"my\">Replace on two</p>";
echo $data, " -------> ";
$repl_counter = 0;
{
$res = $match[0]; // default
if ($repl_counter == 1) // second occurrence
$res = $repl;
$repl_counter++;
return $res;
}, $data);
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