array.prototype.flat is undefined in nodejs : <p>Given is the following js command:</p>

<pre><code>[].flat;
</code></pre>

<p>Executing it in a browser (chrome/firefox): returns <code>function</code></p>

<p>Executing it with nodejs v10.13.0: returns <code>undefined</code></p>

<p>Now I am wondering what other methods are not in the node RTE and where the documentation of global Objects like <code>Array</code> is.</p>

<p>Seems to be the same with <code>Array.prototype.flatMap</code>.</p>
