<?php
$str = 'a[abc][bcd][defg]hi';
$pattern = '/\[(.+)\]/U';
if (preg_match_all($pattern,$str,$match))
{
print_r($match[1]);
}
?>
$str = 'a[abc][bcd][defg]hi';
$pattern = '/\[(.+)\]/U';
if (preg_match_all($pattern,$str,$match))
{
print_r($match[1]);
}
?>
$str = 'a[abc][bcd][defg]hi';
$pattern = '/\[\w+\]/';
print preg_replace($pattern,"2",$str);
?>a222hi