title: jquery return value of a non-existing id or class?
body: <p>I need to check if an object has same id on DOM, because i am trying to create a modal window library,</p>
  
  <p>the problem is in browsers console when i write</p>
  
  <pre><code>$("#anonexistingid");
  </code></pre>
  
  <p>it returns <code>[]</code></p>
  
  <p>but in my code</p>
  
  <pre><code>if($("#"+id)!==[]){
          return;
      }
  </code></pre>
  
  <p>just does not work. What is the proper way of defining an empty array?(Because i think [] means empty array, maybe not i am not sure :D)</p>