Array map returning array of undefined when should return array of objects
<p>Why does </p>

<p><code>['a', 'b', 'c'].map((x) =&gt; { letter: x })</code> returns a array of undefined</p>

<p>and </p>

<p><code>['a', 'b', 'c'].map((x) =&gt; [{ letter: x }][0])</code> returns a array of objects correctly?</p>