jQuery hasClass / addClass Issue

This is what I have. The li has a class of current but for some reason it's not adding the class.

if (jQuery("#sidebar li").hasClass("current")) {
        jQuery(this)开发者_如何学编程.addClass("booyah");
    }

this pointer is not referencing the $("#sidebar li") element.

if (jQuery("#sidebar li").hasClass("current")) {
        jQuery("#sidebar li").addClass("booyah");
    }

The true and easy way: jQuery("#sidebar li.current").addClass('booyah') (If I understood your question, and you want to add 'booyah' to the li element already having 'current')

Try var'ing the side bar el first. I don't think "this" is what you think it is.

var $sideBar = jQuery("#sidebar li");

if ($sideBar.hasClass("current")) {
       $sideBar.addClass("booyah");
    }

Dont use this as you are not in a context where this represents #sidebar li. Instead consolidate your jQuery selector to a variable and reuse the variable. This provides efficiency, as you only need to search for the element in question once, instead of twice.

var sidebarli = jQuery("#sidebar li");
if (sidebarli.hasClass("current")) {
    sidebarli.addClass("booyah");
}

Here you go:

var $li = jQuery("#sidebar li");

if ($li.hasClass("current")) {
        $li.addClass("booyah");
    }

You can also try this: http://jsfiddle.net/shaneburgess/STZUb/

$.each(jQuery("#sidebar li"),function(){
   if (jQuery(this).hasClass("current")) {
        jQuery(this).removeClass("current").addClass("booyah");
    }
});