title: Checking something isEmpty in Javascript?
body: <p>How can I check if a variable is empty in Javascript?</p>
  <pre><code>if(response.photo) is empty {
      do something
  else {
      do something else
  }
  </code></pre>
  <p><code>response.photo</code> was from JSON, and it could be empty sometimes, empty data cells! I want to check if it's empty.</p>