There are an error in the next script. It needs the "endif;" clause but the php ide say nothing!!!
It doesn't produce any output anyway.

<?php
        $people=array(1=>array("name"=>"Jhon","age"=>28),2=>array("name"=>"Barbara","age"=>67));

        foreach($people as &$person)
            if ($person["age"]>=35):
                $person["group"]="old";
            else:
                $person["group"]="young";

        print_r($people);
?>

note: It doesn't produce any output.