3v4l.org

run code in 500+ PHP versions simultaneously
<?php $data = <<<DATA this will = ({match1}) this should = not ({match2}) ({match3}) DATA; $pattern = "~[^\w\s]\h*\K\({\w+}\)~"; preg_match_all($pattern, $data, $matches); print_r($matches[0]);
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11
Array ( [0] => ({match1}) )

preferences:
28.86 ms | 1152 KiB | 7 Q