jQuery looping doesn't seem to work

Question

I am trying to animate a bird wing (to flap a little bit up and down) using the below code:

 $bird_wing_left = $(".bird_wing_left"); function rotate($bodysec) { $bodysec.animate({ transform: "rotate(30deg)" }, 0, function() { $(this).css({ transform: "rotate(70deg)" }); rotate($(this)) ; }); } rotate ($bird_wing_left) ; 

 .bird_wing_left { margin: 50px ; width: 100px ; height: 100px ; background: blue ; } 

 <div class="bird_wing_left"></div> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> 

However, the code doesn't loop. It would just rotate to 70 degrees and stop there. I called the function inside the function so I'm not sure why it's not looping.

Answer 1

Your transform call does nothing because you specify an animation time of 0 . If you want an immediate transformation, use css as in your callback. Moreover, looking at the development console in Chrome showed a too much recursion error, so what you should do is rewrite your code using setInterval :

$bird_wing_left = $(".bird_wing_left");

function rotate ($bodysec) {
  (function () {
    var $_bodysec = $bodysec ;
    var $_angle   = 30 ;
    setInterval (function () {
      $_bodysec.css({
        transform: "rotate(" + $_angle + "deg)"
      });
      $_angle = $_angle == 70 ? 30 : 70 ;
    }, 200) ;

  }) () ;
}

rotate ($bird_wing_left) ;

 $bird_wing_left = $(".bird_wing_left"); function rotate ($bodysec) { (function () { var $_bodysec = $bodysec ; var $_angle = 30 ; setInterval (function () { $_bodysec.css({ transform: "rotate(" + $_angle + "deg)" }); $_angle = $_angle == 70 ? 30 : 70 ; }, 200) ; }) () ; } rotate ($bird_wing_left) ; 

 .bird_wing_left { margin: 50px ; width: 100px ; height: 100px ; background: blue ; } 

 <div class="bird_wing_left"></div> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>