js ドロップダウンメニュー(複数)

<script>
    const hasChild = document.querySelectorAll('.menu-item-has-children');
    const submenu = document.querySelectorAll('.sub-menu');

    for (let i in hasChild) {
        if (hasChild[i]) {
            hasChild[i].addEventListener('mouseover', function() {
                submenu[i].classList.add('down');
                hasChild[i].addEventListener('mouseleave', function() {
                    submenu[i].classList.remove('down');
                });
            });
        }
    }
</script>