title: JavaScript Iterators
body: <p>I was going through MDN (Mozilla Developer Network) and came across <a href="https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Iterators_and_Generators" rel="noreferrer">Iterators and generators</a></p>
  
  <p>So naturally, I tried the snippets of code given in the page on Google Chrome v21.  To be specific, this code:</p>
  
  <pre><code>var it = Iterator(lang);
  for (var pair in it)
    print(pair); // prints each [key, value] pair in turn
  </code></pre>
  
  <p>However, the console returns this error message:</p>
  
  <pre><code>ReferenceError: Iterator is not defined
  </code></pre>
  
  <p>Why's that?  Is the Iterator function deprecated or something? Am I missing a point?  Thank you for your help and time :-)</p>