title: for...of loop. Should I use const or let?
body: <p>When using a for of loop, both of these are allowed and work:</p>
  <pre><code>const numbers = [1,2,3];
  // works
  for(let number of numbers) {
      console.log(number);
  }
  // also works
  for(const number of numbers) {
      console.log(number);
  }
  </code></pre>
  <p>I always use <code>const</code> since I cannot fathom changing the <code>number</code> variable in any context, but when I see a <code>for...of</code> loop in other people's code, it often uses <code>let</code>. Maybe there's a drawback to <code>const</code> that I didn't see? Browser bugs?</p>
  <p>Why use <code>const</code> and when to use <code>let</code> in <code>for...of</code> loops?</p>