Question

I know that you can associate a label with an input using the for and id attributes. However can you use a class and not an id? Thanks

<label for="rooms">Number of rooms</label>
<select id="rooms">
                    <option value="1">1</option>
                    <option value="2">2</option>
                    <option value="3">3</option>
                    <option value="4">4</option>
</select>

Answer 1

Classes are not unique (you can have multiple elements with the same class), so no.

If you want to associate a label to an input without using ID, you can implicitly assign it by including said input inside of the label:

<label>Number of rooms
    <select name="rooms">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
</label>