How to check for undefined type in javascript
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/5515310/is-there-a-standard-function-to-check-for-null-undefined-or-blank-variables-in">Is there a standard function to check for null, undefined, or blank variables in JavaScript?</a>  </p>
</blockquote>



<p>What is the best way to check <code>undefined</code> type in javascript. I know 1 way to check for undefined type i.e. <code>typeOf</code>. But i have to check if for lots of places, so if there is any short and better way to check then please let me know ?</p>

<p>I tried few ways but did`nt get success :</p>

<pre><code>    alert(undefined === "undefined");
    alert(undefined || "defined"); 
</code></pre>
