title: C# Mongodb Driver - How to insert an element into an array at position 0
body: <p>I cannot seem to find a way to insert element at specific index in an array in the Mongodb C# Driver. - For example insert an element at position 0.</p>
  
  <p>The only obvious insert into the array is using the push but that is appending to the end of the array.</p>
  
  <p>I have tried the following but does not work.</p>
  
  <pre><code>var filter = Builders&lt;ChatRoom&gt;.Filter.Eq(Keys.MongoId, ObjectId.Parse(chatRoomId));
  var update = Builders&lt;ChatRoom&gt;.Update.Set(Keys.Comments + ".$.-1", comment);
  </code></pre>
  
  <p>or</p>
  
  <pre><code>var update = Builders&lt;ChatRoom&gt;.Update.Push(Keys.Comments+".-1",comment);
  </code></pre>
  
  <p>But it doesn't work. Also I cannot seem to find the $position operator in the Mongodb C# docs. - was hoping that could help, if it was relevant.</p>