public function extension()
    {
        $atoms = $this->nameAtoms();
        $numParts = count($atoms);

        if ($numParts > 1) {
            return $atoms[$numParts - 1];
        }

        return null;
    }
public function extension()
    {
        $atoms = $this->nameAtoms();
        $numParts = count($atoms);

        if ($numParts > 1) {
            return $atoms[$numParts - 1];
        }

        return null;
    }
public function extension ( ) { $ atoms = $ this -> nameAtoms ( ) ; $ numParts = count ( $ atoms ) ; if ( $ numParts > 1 ) { return $ atoms [ $ numParts - 1 ] ; } return null ; }
Get this path's last extension.

@return string|null The last extension of this path's last atom. If the last atom has no extensions, or this path has no atoms, this method will return null.
Get this path s last extension .