title: Array.prototype.flat() is not working in command line using Node JS
body: <p>I am trying to test the array.flat method inside Visual Studio code using node js from the command line. When I run the code i get:</p>
  
  <blockquote>
    <p>"TypeError: arr.flat is not a function" </p>
  </blockquote>
  
  <p>I have ran the code in chrome and am able to get the desired result (a flattened array)</p>
  
  <p>Note: Even after updating node js to the latest version, it is still not working.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var arr1 = [1, 2, [3, 4]];
  arr1.flat(); 
  console.log(arr1)</code></pre>
  </div>
  </div>
  </p>