题解 | #无重复数组#

    <script>
        var cups = [
            { type: 1, price: 100, color: 'black', sales: 3000, name: '牛客logo马克杯' },
            { type: 2, price: 40, color: 'blue', sales: 1000, name: '无盖星空杯' },
            { type: 4, price: 60, color: 'green', sales: 200, name: '老式茶杯' },
            { type: 3, price: 50, color: 'green', sales: 600, name: '欧式印花杯' }
        ]
        var ul = document.querySelector('ul');
        var upbtn = document.querySelector('.up');
        var downbtn = document.querySelector('.down');
        // 补全代码
upbtn.onclick = function(){
  cups.sort((a,b)=>{
    return a.sales - b.sales
  })
  showLi()
}
downbtn.onclick = function(){
  cups.sort((a,b)=>{
    return b.sales - a.sales
  })
  showLi()
}
function showLi() {
  ul.innerHTML = ''
   for (let i = 0; i < cups.length; i++) {
  ul.innerHTML += `<li>${cups[i].name}</li>\n`
}
}
        
    </script>
</body>