How can i remove a specified field from a mongoose document?
<p>I would like to remove dynamically a field from a mongoose document.</p>

<p><strong>What I have tried:</strong>
I am using</p>

<pre><code>$unset
</code></pre>

<p>and when I type the value</p>

<pre><code>"cars.BMW"
</code></pre>

<p>it works. But when I want to pass a parameter, which will be a car brand and then to unset it. I tried</p>

<pre><code>{$unset: {"cars."+brand: " "}}
</code></pre>

<p>but the plus sign is unexpected.</p>