title: Perform a `typeof JSON` comparison
body: <p>I have a method that receives something and it needs to determine the type of the received value. I can use the <code>typeof</code> thing to perform regular comparisons like if it is a number or a string. But how can I do this for JSON objects? Comparing them with <code>JSON</code> brings up the error:</p>
  
  <blockquote>
    <p>Uncaught TypeError: Expecting a function in instanceof check, but got  #&lt; Object></p>
  </blockquote>
  
  <p>So I guess that comparing a JSON object type with <code>JSON</code> is not the way?</p>
  
  <p>The original code is like:</p>
  
  <pre><code>check = (what) -&gt;
    if what instanceof JSON
      alert "Yooo"
  
  check({compare: "me"})
  </code></pre>