title: Not able to iterate over Map objects in Firefox console: undefined
body: <p>Still new to Javascript.</p>
  <p>I tried iterating over a Map object and printing the keys/values in the console. However it just returns undefined, even if I use the example from the Mozilla firefox documentation. <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map" rel="nofollow noreferrer">https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map</a></p>
  <p>eg,</p>
  <pre><code>const myMap = new Map()
  myMap.set(0, 'zero')
  myMap.set(1, 'one')
  
  for (const [key, value] of myMap) {
    console.log(key + ' = ' + value)
  }
  </code></pre>
  <p>Does anybody know what might the problem here?</p>
  <p>It seems to work on Chrome, but in Firefox console (Ubuntu VM) it only returns undefined.</p>
  <p><a href="https://i.imgur.com/AyKKFpa.png" rel="nofollow noreferrer"><img src="https://i.imgur.com/AyKKFpa.png" alt="Screenshot of console that contains the code but no output." /></a></p>