Symfony3 / Twig模板：数据库对象到表

I'm just learning Symfony3 and Twig. Unsure what I'm doing wrong, but I have a DB table product with rows 'name', 'price' and 'description'. I want to simply dump the DB table into an HTML table. I did as follows:

Twig:

<table>
    {% for product in products %}
        <tr>
            {% for key,value in product %}
                <td>{{ value }}</td>
            {% endfor %}
        </tr>
    {% endfor %}
</table>

if I dump product at the beginning of the first for-loop, I get the following result:

Product {#330 ▼
  -id: 1
  -name: "Keyboard"
  -price: "19.99"
  -description: "Ergonomic and stylish!"
}

however, key and value are both empty.

You should use something like this:

<table>
    <tr>
        <th>Name</th> <th>Price</th> <th>Description</th>
    </tr>
    {% for product in products %}
        <tr>
            <td>{{ product.getName }}</td>
            <td>{{ product.getPrice }}</td>
            <td>{{ product.getDescription }}</td>
        </tr>
    {% endfor %}
</table>

The code depends on your getters.