in React + Redux, when should use response.json()
<p>from the official example, the fetch data from server is done like this:</p>

<pre><code>function fetchPosts(subreddit) {
  return dispatch =&gt; {
    dispatch(requestPosts(subreddit))
    return fetch(`http://www.reddit.com/r/${subreddit}.json`)
      .then(response =&gt; response.json())
      .then(json =&gt; dispatch(receivePosts(subreddit, json)))
  }
}
</code></pre>

<p>so when should I use <code>response =&gt; response.json()</code>? I have checked the <a href="https://developer.mozilla.org/en-US/docs/Web/API/Body/json" rel="nofollow">mdn</a>, but still not clear.</p>