title: How to write this JS function in best(smartest) way?
body: <p>I would like to write the function which takes file size in bytes(7762432) and return value in user readable format (7,762,432 bytes).</p>
  
  <pre><code>function(fileSizeBytes){
      // mind blowing logic :)
      return userReadable;
  }
  </code></pre>
  
  <p>I have done it using old school string split way, but i am just curious if there exist way that can blow my head and make me scream with "O god it can be done this way too !!"</p>