题解 | #数组排序#

upbtn.onclick = function() {
    sortName(0);
}
downbtn.onclick = function() {
    sortName(1);
}

function sortName(type) {
    let data = [...cups];
    let fn;
    let fragment = document.createDocumentFragment();
    if (!type) {
        fn = (a, b) => a.sales - b.sales;
    } else {
        fn = (a, b) => b.sales - a.sales;
    }
    data.sort(fn).map(item => {
        let li = document.createElement('li');
        li.innerText = item.name;
        fragment.appendChild(li);
    })
    ul.innerHTML = '';
    ul.appendChild(fragment);
}