javascript - 函数根据作为参数的日历日期返回两个日历日期以表示星期一的日期和星期日的日期

Question

你能帮我一个函数接收一个参数，即日历日期（12.4.2020）并返回两个代表星期一和星期日日期的日期（11.30.2020 - 12.06.2020）。

到目前为止我所拥有的是：

function getWeek(d){
 findDayOfWeek = new Date(d).getDay(); // for exemple if d is 12.04.2020 that line will return 5 that mean friday
}

但现在我被阻止了。我不知道如何继续。

谢谢！

Answer 1

您可以创建 2 个返回 firstDayOfWeek 和 lastDayOfWeek 之类的函数

function firstDayOfWeek(dateObject, firstDayOfWeekIndex) {

    const dayOfWeek = dateObject.getDay(),
        firstDayOfWeek = new Date(dateObject),
        diff = dayOfWeek >= firstDayOfWeekIndex ?
            dayOfWeek - firstDayOfWeekIndex :
            6 - dayOfWeek

    firstDayOfWeek.setDate(dateObject.getDate() - diff)
    firstDayOfWeek.setHours(0,0,0,0)

    return firstDayOfWeek
}

和

function lastDayOfWeek(dateObject, lastDayOfWeekIndex) {

    const dayOfWeek = dateObject.getDay(),
        lastDayOfWeek = new Date(dateObject),
        diff = dayOfWeek <= lastDayOfWeekIndex ?
            dayOfWeek - lastDayOfWeekIndex :
            6 - dayOfWeek

    lastDayOfWeek.setDate(dateObject.getDate() - diff)
    lastDayOfWeek.setHours(0,0,0,0)

    return lastDayOfWeek
}

现在你可以调用这些函数

let lastMonday = firstDayOfWeek(new Date(), 1)
let nextSunday = lastDayOfWeek((new Date(), 7)