//Some useful regular expression pattern for our daily need in web applications//
$string="hikiran hellokiran iam kiran hellos hellosdsdsd ima ";
$pattern = "/(hi|hello)(kiran)/"; ///
preg_match_all($pattern,$string,$match); //aray zero will give exact match results array one will gives matches for first () parenthsessi array 2 give matches for parenthisis ()//