How to properly use the each() in jQuery?

I have the following:

  <div class="io-section-header">
  <ul>
    <li class="advanced">Eat</li>
    <li class="advanced">Sleep</li>开发者_JAVA技巧;
    <li class="advanced">Be merry</li>
  </ul>
 </div>

I have the jQuery (which is tied to a click() handler:

$('io-section-header').each(function() {
                $("li").siblings(".advanced").toggle('fast',function(){});
            });

Why aren't the list items toggling?

I dont think you actually need the each() statement for what you are trying to do. This should work fine.

$('.io-section-header li').siblings(".advanced").toggle('fast');

here is a fiddle http://jsfiddle.net/8kpcn/1/

In fact this will do the same thing as well

$('.io-section-header li.advanced').toggle('fast');

http://jsfiddle.net/8kpcn/2/

You just need to add a dot before your class selector.

$('.io-section-header').each(function() {
                $("li").siblings(".advanced").toggle('fast',function(){});
});

jsFiddle

Try this:

$('.io-section-header li').each(function() {
    $(this).siblings(".advanced").toggle('fast');
});

jsFiddle

The callback function needs some parameters.

$('.io-section-header').each(function(index, Element) {
    //Do whatever you need to do with each of them here.
    //The current element in this iteration is in `Element`
});