You can toggle classes using the classList.toggle()
function:
var element = document.getElementById('sidebar');
var trigger = document.getElementById('js-toggle-sidebar'); // or whatever triggers the toggle
trigger.addEventListener('click', function(e) {
e.preventDefault();
element.classList.toggle('sidebar-active'); // or whatever your active class is
});
That should do everything you need – if you have more than one trigger I’d recommend using document.querySelectorAll(selector)
instead.