Question

Based on this answer – how to change classes on click
can somebody explain me what exactly the code below is doing?

$("a").click(function() {
  var $this = $(this); // this is just for performance
  if(!$this.hasClass('yy'))
    $('.yy').toggleClass("yy").toggleClass("xx");
  $this.toggleClass("yy").toggleClass("xx");
});

I mean the last two lines.

Answer 1

First, it finds all of the a elements (links).

It sets their on-click actions to a function which:

1. checks to see if that link currently has the yy CSS class.

2. If it doesn’t, then it turns off the yy class on everything which has it and toggles the xx on those that used to have the yy class.

3. After that, it toggles the yy and xx classes on the link that was clicked.