So my approach would be something like:

$(‘body’).toggleClass(‘changePw’);

and then in my css:

.view-on-change-pw {display:none;}
.changePw .view-on-change-pw { display:block; }

I oftentimes pass a boolean to toggleClass in these instances, as I know what direction I want things to go in.

(The obvious downside is that I need to specify the display value of the elements, but I’m typically using this on ‘block’ containers anyhow.)

But I like 1) having the DOM represent current state 2) keeping separation of presentation and behavior and 3) it’s super fast.