题解 | #数组过滤#

     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');
            // 补全代码
            select.onchange = function (e) {
        let option = this.value;
        let arr = [];
        if (option === "1") {
          arr = cups.filter((item) => {
            return item.sales < 100;
          });
        } else if (option === "2") {
          arr = cups.filter((item) => {
            return item.sales >= 100 && item.sales <= 500;
          });
        } else {
          arr = cups.filter((item) => {
            return item.sales > 500;
          });
        }
        show(arr);
      };
      function show(array) {
        ul.innerHTML = "";
        array.forEach((item) => {
          let li = document.createElement("li");
          li.innerText = item.name;
          ul.append(li);
        });
      }