You can just add an else clause to your existing event listener and call classList.remove
window.addEventListener('scroll', function() { var elementTarget = document.querySelector('.section-2'); if (window.scrollY > (elementTarget.offsetTop + elementTarget.offsetHeight)) { document.querySelector('.section-3').classList.add('anotherclass'); } else { document.querySelector('.section-3').classList.remove('anotherclass'); } });
window.addEventListener('scroll', function() { if (window.scrollY > 100) { document .querySelector('.section-3') .classList.remove('sticky-invisible'); document .querySelector('.section-3') .classList.add('sticky-visible'); } else { document .querySelector('.section-3') .classList.remove('sticky-visible'); document .querySelector('.section-3') .classList.add('sticky-invisible'); } });