javascript Date()，从工作日数组中渲染，由 Date().getDay() 选择索引，reactjs

Question

慈善和明智的响应者，为什么代码块底部的 {WEEK_DAYS[weekdayname.getDay()]} 不根据用户所在的日期呈现工作日？

我需要插入一些吗？我已经尝试过这个大部分了

export const WEEK_DAYS = {
    Sun: "Sun",
    Mon: "Mon",
    Tue: "Tue",
    Wed: "Wed",
    Thu: "Thu",
    Fri: "Fri",
    Sat: "Sat"
}

class CalSlideDrawer extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      date: new Date(),
      day: new Date().getDate(),
      month: +new Date().getMonth(),
      year: +new Date().getFullYear(),
    };
  }
// insert user generated state changes of the date in view
render() {
  const weekdayname = new Date(this.state.year, this.state.month, this.state.day);
  <div className="weekday">{WEEK_DAYS[weekdayname.getDay()]}</div>
}

截至询问时，{WEEK_DAYS[weekdayname.getDay()]} 呈现为空白。

Go to src>UIConainers>Calendar>CalSlideDrawer.js

https://codesandbox.io/s/zen-dijkstra-1c31n?fontsize=14

CalSlideDrawer.js 可通过左上角的 Logo 图标找到(如果您在紫色屏幕上启动，则按收件箱图标后)

非常感谢

Answer 1

Date.getDat()返回 0-6 之间的数字，代表周日至周六。 将您的 WEEK_DAYS 对象更改为数组:

export const WEEK_DAYS = [
    "Sun",
    "Mon",
    "Tue",
    "Wed",
    "Thu",
    "Fri",
    "Sat"
];