for (var i = 0; i < this.button_list.length; i++) { if (i !== index) { document.getElementById('factory' + i).classList.remove('on'); document.getElementById('factory' + i).classList.add('sx_child'); } else { document.getElementById('factory' + i).classLi

这段代码有语法错误，最后一行缺少了闭合的大括号。正确的代码如下：

for (var i = 0; i < this.button_list.length; i++) {
  if (i !== index) {
    document.getElementById('factory' + i).classList.remove('on');
    document.getElementById('factory' + i).classList.add('sx_child');
  } else {
    document.getElementById('factory' + i).classList.add('on');
    document.getElementById('factory' + i).classList.remove('sx_child');
  }
}

这段代码的功能是遍历一个按钮列表，根据索引值设置相应的CSS类。如果当前索引不是目标索引，就添加 'sx_child' 类，移除 'on' 类；否则添加 'on' 类，移除 'sx_child' 类。

相关问题

帮我优化这段代码 window.onload = function () { function hotChange() { let current_index = 0; let timer = window.setInterval(antoChange, 3000); const button_li = document.getElementById("button").getElementsByTagName("li"); const pic_li = document.getElementById("banner_pic").getAttributeNames("li"); for (var i = 0; i < button_li.length; i++) { button_li[i].onmouseover = function () { if (timer) { clearInterval(timer); } for (var j = 0; j < pic_li.length; j++) { if (button_li[j] == this) { current_index = j; button_li[j].className = "current"; pic_li[j].className = "current"; } else { pic_li.className = "pic"; button_li[j].className = "but"; } } } button_li[i].onmouseover = function () { timer = setInterval(antoChange, 3000); } } function antoChange() { ++current_index; if (current_index == button_li.length) { current_index = 0; } for (var i = 0; i < button_li.length; i++) { if (i == current_index) { button_li[i].className = "current"; pic_li[i].className = "current"; } else { button_li[i].className = "but"; pic_li[i].className = "pic"; } } } } hotChange(); }

可以尝试以下优化：

1. 如果能使用现代的 JavaScript，可以使用 const 和 let 声明变量，而不是使用 var。

2. 获取 DOM 元素时，尽量避免多次获取相同的元素，可以将其存储到一个变量中。

3. 给按钮绑定 mouseover 和 mouseout 事件时，可以使用 mouseenter 和 mouseleave 事件来替代，这样更加准确。

4. 给按钮绑定事件时，可以使用事件委托的方式，减少事件绑定的次数。

下面是代码优化后的示例：

window.onload = function() {
  const buttonList = document.querySelectorAll('#button li');
  const picList = document.querySelectorAll('#banner_pic li');
  let currentIndex = 0;
  let timer = setInterval(antoChange, 3000);

  function hotChange() {
    for (let i = 0; i < buttonList.length; i++) {
      buttonList[i].addEventListener('mouseenter', function() {
        clearInterval(timer);
        currentIndex = i;
        changePic();
      });
      buttonList[i].addEventListener('mouseleave', function() {
        timer = setInterval(antoChange, 3000);
      });
    }
  }

  function antoChange() {
    currentIndex = (currentIndex + 1) % buttonList.length;
    changePic();
  }

  function changePic() {
    for (let i = 0; i < buttonList.length; i++) {
      if (i === currentIndex) {
        buttonList[i].className = 'current';
        picList[i].className = 'current';
      } else {
        buttonList[i].className = 'but';
        picList[i].className = 'pic';
      }
    }
  }

  hotChange();
}

<template> <div id="bar1" style="width:1200px; height:800px"> <button @click="getData">获取API数据</button> <button @click="processData">处理数据</button> </div> </template> <script> import * as echarts from "../src/assets/echarts.min"; import axios from "axios"; export default { name: "Bar1", data() { return { list: [], map: new Map(), huabeiData: [], x_data: [], y_data: [], }; }, methods: { getData() { axios .post("/api/dataVisualization/selectOrderInfo", { startTime: "2020-01-01 00:00:00", endTime: "2020-12-30 00:00:00", }) .then((result) => { this.list = result.data.data; console.log(result.data.data); }) .catch((err) => { console.log(err); }); }, processData() { let list = this.list; function classify(list) { let map = {}; let myArr = []; for (var i = 0; i < list.length; i++) { if (!map[list[i].regionName]) { myArr.push({ regionName: list[i].regionName, data: [list[i]], }); map[list[i].regionName] = list[i]; } else { for (var j = 0; j < myArr.length; j++) { if (list[i].regionName === myArr[j].regionName) { myArr[j].data.push(list[i]); break; } } } } return myArr; } console.log(classify(list)); var classifiedList = classify(list); console.log(classifiedList, "数组"); var allMedians = []; for (var i = 0; i < classifiedList.length; i++) { var regionData = classifiedList[i].data; var amounts = []; for (var j = 0; j < regionData.length; j++) { amounts.push(regionData[j].finalTotalAmount); } amounts.sort((a, b) => b - a); console.log(amounts, "顺序"); var median; var length = amounts.length; if (length % 2 === 0) { median = (amounts[length / 2 - 1] + amounts[length / 2]) / 2; } else { median = amounts[Math.floor(length / 2)]; } allMedians.push({ regionName: classifiedList[i].regionName, median: median, }); } console.log(allMedians); for(let i of allMedians){ this.x_data.push(i.regionName) this.y_data.push(i.median) } console.log(this.x_data) console.log(this.y_data) let barChart = echarts.init(document.getElementById("bar1")) const option = { xAxis:{ type:'category', data:this.x_data }, yAxis:{ type:'value', }, series:[ { data:this.y_data, type:'bar' } ] }; option && barChart.setOption(option,true); }, }, }; </script>这段代码还有需要修改的地方吗，请表明理由

在这段代码中，还有一处需要修改的地方。请将 `echarts` 的导入语句更改为 `import echarts from "echarts"`。原因是在导入 `echarts` 库时，使用的是默认导出（`export default`），因此需要使用 `import echarts from "echarts"` 来导入正确的模块。

修正后的代码如下所示：

<template>
  <div id="bar1" style="width:1200px; height:800px">
    <button @click="getData">获取API数据</button>
    <button @click="processData">处理数据</button>
  </div>
</template>

<script>
import echarts from "echarts";
import axios from "axios";

export default {
  name: "Bar1",
  data() {
    return {
      list: [],
      map: new Map(),
      huabeiData: [],
      x_data: [],
      y_data: [],
    };
  },
  methods: {
    getData() {
      axios
        .post("/api/dataVisualization/selectOrderInfo", {
          startTime: "2020-01-01 00:00:00",
          endTime: "2020-12-30 00:00:00",
        })
        .then((result) => {
          this.list = result.data.data;
          console.log(result.data.data);
        })
        .catch((err) => {
          console.log(err);
        });
    },

    processData() {
      let list = this.list;

      function classify(list) {
        let map = {};
        let myArr = [];
        for (var i = 0; i < list.length; i++) {
          if (!map[list[i].regionName]) {
            myArr.push({
              regionName: list[i].regionName,
              data: [list[i]],
            });
            map[list[i].regionName] = list[i];
          } else {
            for (var j = 0; j < myArr.length; j++) {
              if (list[i].regionName === myArr[j].regionName) {
                myArr[j].data.push(list[i]);
                break;
              }
            }
          }
        }
        return myArr;
      }

      console.log(classify(list));

      var classifiedList = classify(list);
      console.log(classifiedList, "数组");

      var allMedians = [];

      for (var i = 0; i < classifiedList.length; i++) {
        var regionData = classifiedList[i].data;
        var amounts = [];
        for (var j = 0; j < regionData.length; j++) {
          amounts.push(regionData[j].finalTotalAmount);
        }
        amounts.sort((a, b) => b - a);
        console.log(amounts, "顺序");
        var median;
        var length = amounts.length;
        if (length % 2 === 0) {
          median =
            (amounts[length / 2 - 1] + amounts[length / 2]) / 2;
        } else {
          median = amounts[Math.floor(length / 2)];
        }
        allMedians.push({
          regionName: classifiedList[i].regionName,
          median: median,
        });
      }
      console.log(allMedians);
      for (let i of allMedians) {
        this.x_data.push(i.regionName);
        this.y_data.push(i.median);
      }
      console.log(this.x_data);
      console.log(this.y_data);

      let barChart = echarts.init(document.getElementById("bar1"));
      const option = {
        xAxis: {
          type: "category",
          data: this.x_data,
        },
        yAxis: {
          type: "value",
        },
        series: [
          {
            data: this.y_data,
            type: "bar",
          },
        ],
      };
      option && barChart.setOption(option, true);
    },
  },
};
</script>

以上是修正后的代码。除了将 `echarts` 的导入语句更改为 `import echarts from "echarts"` 外，没有其他需要修改的地方。修正后的代码应该可以正确执行，并生成柱状图。