function collapseMenu() {
let menu = document.querySelector(".menu");
let menuChildren = menu.querySelectorAll('li');
let i = menuChildren.length - 1;
let other = document.createElement("li");
other.setAttribute("onclick", "submenu(this)");
other.id = 'other';
other.innerHTML = 'More';
let submenu = document.createElement("ul");
submenu.classList.add('submenu', 'hidden');
other.appendChild(submenu);
if (menu.offsetWidth >= window.innerWidth) {
let drop;
if (!menu.contains(document.getElementById('other'))) {
menu.appendChild(other);
}
while (menu.offsetWidth >= window.innerWidth) {
drop = menu.removeChild(menuChildren[i]);
submenu.prepend(drop);
i--;
}
} else {
//On increase window
}
}
collapseMenu();
window.addEventListener('resize', collapseMenu);
Please help, thanks