What does `app.use(bodyParser.json())` do?
<p>For:</p>

<pre><code>bodyParser.urlencoded({extended: ...})
</code></pre>

<p>my research shows me that if <code>extended: true</code>, then you can parse nested objects, or generally any type. However, if you set <code>extended: false</code>, then you can only parse strings or arrays. But what does ...</p>

<pre><code>app.use(bodyParser.json())
</code></pre>

<p>mean exactly? I mean, yes... I know the docs mention that it parses json. But I am still confused. I have noticed applications that set <code>extended: true</code> do NOT use <code>bodyParser.json()</code> at all. But applications that <code>extended: false</code> tend to use <code>bodyParser.json()</code>. Why is this? At the end of the day, both applications are able to parse json.</p>

<p>Secondly, which is the recommended approach?</p>