php class F_FileIterator extends FilterIterator private ext private it

<?php 
class F_FileIterator extends FilterIterator { 
    private $ext; 
    private $it; 

    function __construct(DirectoryIterator $it, $ext) { 
        parent::__construct($it); 
        $this->it=$it; 
        $this->ext=$ext; 
    } 

    function accept() { 
        $ext=pathinfo($this->current(),PATHINFO_EXTENSION); 
        return ($ext==$this->ext) ? true : false; 
    } 
} 

$d=new F_FileIterator(new DirectoryIterator('.'), 'php'); 

foreach ($d as $v) { 
    echo "$v<br />\n"; 
} 
?>