interface Element {
    public function characteristics();
}
class Water implements Element {
    public function characteristics() {
        return [
            'Water characteristic 1',
            'Water characteristic 2',
            'Water characteristic 3',    
        ];
    }
}
class Fire implements Element {
    public function characteristics() {
        return [
            'Fire characteristic 1',
            'Fire characteristic 2',
            'Fire characteristic 3',    
        ];
    }
}
class Air implements Element {
    public function characteristics() {
        return [
            'Air characteristic 1',
            'Air characteristic 2',
            'Air characteristic 3',    
        ];
    }
}
class Earth implements Element {
    public function characteristics() {
        return [
            'Earth characteristic 1',
            'Earth characteristic 2',
            'Earth characteristic 3',    
        ];
    }
}


function describe(Element $element) {
    echo get_class($element) . "\n";
    $characteristics = $element->characteristics();
    if (is_array($characteristics)) {
        foreach ($characteristics as $characteristic) {
            echo $characteristic . "\n";
        }
        echo "\n\n";
    }
}

$element = new Water;
describe($element);

$element = new Fire;
describe($element);

$element = new Air;
describe($element);

$element = new Earth;
describe($element);