Javascript setTimeout issue

I have a bar that shows up (in rails) from a flash hash. I want it to explode with jquery, so I added this code:

<script>
setTimeout("derp()", 2000);

function derp() {
     $("span").hide("explode", { pieces: 16 }, 500);
}

</script>

Works fine except in a couple of seconds it appears again and then something extremely strange happens - th开发者_如何学Ce path to googleapis is shown and the page becomes barely responsive. What gives?

This is the proper way of using setTimeout

<script type='text/javascript'> 

    setTimeout(function () {
      $("span").hide("explode",{ pieces: 16 }, 500); 
    }, 2000);  

</script> 

running it the way you had is like using eval(), you should avoid passing a string in setTimeout()

you could also pass your function like this:

setTimeout(derp,500);