我想从封装的角度完成这道题，只需给一个范围值 筛选即可。有没有更好的方法。

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
    </head>
    <body>
        <select name="" id="">
            <option value="0">请选择销量范围</option>
            <option value="1"><100</option>
            <option value="2">100~500</option>
            <option value="3">>500</option>
        </select>
        <ul>
            <li>牛客logo马克杯</li>
            <li>无盖星空杯</li>
            <li>老式茶杯</li>
            <li>欧式印花杯</li>
        </ul>

        <script>
            var cups = [
                { type: 1, price: 100, color: 'black', sales: 60, name: '牛客logo马克杯' },
                { type: 2, price: 40, color: 'blue', sales: 100, 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 select = document.querySelector('select');
            var ul = document.querySelector('ul');

            select.onchange = (e) => {
              const index = select.value
              const currentCup = cups
              let newCups = []

              switch(index) {
                case '1': 
                  newCups = filterCup(0, 100)
                  break
                case '2': 
                  newCups = filterCup(100, 500, true)
                  break
                case '3': 
                  newCups = filterCup(500, '')
                  break
                default:
                  newCups = cups
              }

              // 渲染
              let s = ``
              for (const item of newCups) {
                s += `<li>${item.name}</li>`
              }
              ul.innerHTML = s
            }

            function filterCup(min, max, contain) { // contain是否个范围值  包含自身
              if (contain) {
                min --
                max ++
              }
              return cups.filter(c => max ? (c.sales > min && c.sales < max) : c.sales > min)
            }
        </script>
    </body>
</html>