Reverse all the content wrapped by parenthesis

reverse_parenthesis.php

<?php

$string = '12(345)6(78)8(012(34(56)7))0123';

$regex = '/(\(\w+\))/';

$result = $string;

while( strpos($resultado,'(') !== false) {
    $result = preg_replace_callback($regex, function($matches) {
        return strrev(substr($matches[1],1,-1));
    }, $result);
}
echo 'Original: ',$string;
echo PHP_EOL;
echo 'Result: ',$resulta;