title: unable to use regex in $in operator in mongodb
body: <p>I am trying to use the <code>regex</code> with <code>$in</code> operator as mentioned in the docs but I am still unable to get the value.</p>
  
  <p><code>db.users.find({'profile.firstName':{$in:["/justin/i"]}}).count() = 0</code></p>
  
  <p>but when I used like this </p>
  
  <p><code>db.users.find({'profile.firstName':{$in:["justin"]}}).count()=1</code>
  and </p>
  
  <p><code>db.users.find({'profile.firstName':{$in:["Justin"]}}).count()=2</code>  </p>
  
  <p><strong>Edited Question</strong></p>
  
  <p>seems like I am not clear with the question I will add the code for easy understanding</p>
  
  <p>I am trying to get the list of documents from a query which is case insensitive.I think it better to explain my doubt with code.</p>
  
  <p><code>Meteor.users.find({'profile.firstName':{$in:[/justin/i,/helen/i]}}).count()</code></p>
  
  <p><strong>will give documents whose <code>profile.firstName</code> is <code>justin/Justin/JUSTIn/HElen/helen</code></strong></p>
  
  <p>but my doubt how to give the variable <code>x=["sai","test","jacob",---etc]</code> in place of <code>helen/justin</code></p>