如何在 JavaScript 中查找星期几

Question

我正在尝试查找从今天到星期日的工作日。由于今天是星期一，我想显示从星期一到星期日的日期，但明天，我希望我的程序在星期二到星期日运行。

dateSets() {
            let firstDayOfWeek = "";
            let dates = [];
            firstDayOfWeek = new Date();
                let sunday = new Date();
                sunday.setDate(sunday.getDate() - sunday.getDay() + 7);
                const diff = sunday.getDate() - firstDayOfWeek.getDate();
                dates.push(new Date());
                for (let i = 0; i < diff; i++) {
                    dates.push(
                        new Date(firstDayOfWeek.setDate(firstDayOfWeek.getDate() + 1))
                    );
                }
            return dates;
        },

这是查找星期几的另一个函数：

getDateOfWeek(week, year) {
            let simple = new Date(year, 0, 1 + (week - 1) * 7);
            let dow = simple.getDay();
            let weekStart = simple;
            if (dow <= 4) weekStart.setDate(simple.getDate() - simple.getDay() + 1);
            else weekStart.setDate(simple.getDate() + 8 - simple.getDay());
            return weekStart;
        },

但是它没有像我预期的那样工作，在数据集中，只显示星期一而不显示其他日期，我不明白原因。如果你能帮我解决这个问题，我会很高兴。谢谢...

Answer 1

这是您的选择，但如果您安装 NodeJS 并在 cmd 中打开您的文件夹并输入 'npm init' 和 'npm I days' 并打开您的编辑器并输入

var days = require('days');
console.log(days); // ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

控制台将显示一周中的所有日子，如果您想要特定的一天，您可以执行以下操作

var days = require('days');
console.log(days[0]);  //Sunday

如果您在安装 NodeJS 方面需要帮助，请观看 YouTube 视频或回复此评论，我会提供帮助

Answer 2

let firstDayOfWeek = "";
let dates = [];
firstDayOfWeek = new Date();
    let sunday = new Date();
    sunday.setDate(sunday.getDate() - sunday.getDay() + 7);
    //const diff = sunday.getDate() - firstDayOfWeek.getDate();
    //Try this code
    var timeDiff = Math.abs(sunday.getTime() - firstDayOfWeek.getTime());
    var diff = Math.ceil(timeDiff / (1000 * 3600 * 24)); 
    dates.push(new Date());
    for (let i = 0; i < diff; i++) {
        dates.push(
            new Date(firstDayOfWeek.setDate(firstDayOfWeek.getDate() + 1))
        );
    }
return dates;

Answer 3

function getWeekDates(){
  const dates = [new Date()]; // today
  const curr = new Date();
  const remDaysCount = 7-curr.getDay();
  for(let i=1; i<= remDaysCount; i++){
    // increase current Date by 1 and set to current Date
      const nextDate = curr.setDate(curr.getDate()+1);
    dates.push(new Date(nextDate));
  }
  return dates;
}

console.log(getWeekDates());

Answer 4

您的问题在这里：

const diff = sunday.getDate() - firstDayOfWeek.getDate()

当前日期是 9 月 27 日，下周日是 10 月 3 日，所以 diff 是 -4，for 循环测试 i < diff 从一开始就是错误的。考虑使用循环并将日期从今天递增到星期日。

function getDaysToSunday(date = new Date()) {
  let d = new Date(+date);
  let result = [];
  do {
    result.push(new Date(+d));
    d.setDate(d.getDate() + 1);
  } while (d.getDay() != 1)
  return result;
}

console.log(getDaysToSunday().map(d=>d.toDateString()));

如何在 JavaScript 中查找星期几

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