- array_slice: documentation ( source)
- preg_match_all: documentation ( source)
- var_export: documentation ( source)
<?php
$string='Demo #1: (11 steps)[1] and Demo #2: (35 steps)[2]';
var_export(preg_match_all('~\(([^)]*)\)\[([^\]]*)]~',$string,$out)?array_slice($out,1):[]);