title: How to start setInterval loop immediately?
body: <p>In a simple <code>setInterval</code></p>
  
  <pre><code>setInterval(function() {
        // Do something every 9 seconds
  }, 9000);
  </code></pre>
  
  <p>The first action will happen after 9 seconds (<code>t=9s</code>). How to force the loop to perform the first action immediately (<code>t=0</code>)?</p>
  
  <p>I think it is due to the mechanism of <code>setInterval</code> to have <code>Delay - Action - Delay - Action ...</code> loop; instead of <code>Action - Delay - Action - Delay ...</code> loop.</p>
  
  <p><strong>EDIT:</strong> My function is indeed a loop as</p>
  
  <pre><code>setInterval(function(){
  $('.test').each(function(idx){
      var duration = 1000;
      $(this).delay(duration*idx);
      Some stuff here
  });
  }, 4000);
  </code></pre>