JS-获取本周的日子

Question

我正在尝试创建一个函数来获取当天的所有日期。我有一个我认为正常工作的功能，直到我注意到如果一周中的某一天接近月末，比如二月，我得到了奇怪的数据。有谁知道发生了什么以及如何解决它？

function days(current) {
  var week = new Array();
  // Starting Monday not Sunday 
  var first = ((current.getDate() - current.getDay()) + 1);
  for (var i = 0; i < 7; i++) {
    week.push(
      new Date(current.setDate(first++))
    );
  }
  return week;
}

var input = new Date(2017, 1, 27);
console.log('input: %s', input);

var result = days(input);
console.log(result.map(d => d.toString()));

.as-console-wrapper{min-height:100%}

Answer 1

如果你不想使用像Moment.js这样的其他类库，你也可以稍微改变一下你的功能，然后就可以了。试试这个：

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function dates(current) {
    var week= new Array(); 
    // Starting Monday not Sunday
    current.setDate((current.getDate() - current.getDay() +1));
    for (var i = 0; i < 7; i++) {
        week.push(
            new Date(current)
        ); 
        current.setDate(current.getDate() +1);
    }
    return week; 
}
console.log(dates(new Date(2017, 1, 27)));

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Answer 2

我将使用您2017年2月27日的示例跟踪您的代码：

first = 27 - 1 + 1 = 27

loop:

Feb.setDate(27) = 27 feb
Feb.setDate(28) = 28 feb
Feb.setDate(29) = Not 29 days in Feb. So it sets current to 29-28 = 1st day of March
March.setDate(30) = March 30
March.setDate(31) = March 31     
March.setDate(32) = Not 32 days in March. So it sets current to 31-32 = 1st of April..
April.setDate(33) = Not 33 days in April. So it sets current day 33-30 = 3rd day of May. 

请注意我使用Month.setDate()的简写来显示current Date对象的月份。

所以问题在于您对当前使用的setDate的理解。它会更改月份，如果您使用的值不是该月的某一天，则会适当调整月份和日期。我希望这能为你解决问题。

有关如何将日期添加到日期，请参阅Add +1 to current date。根据您的代码，您可以将当前设置为一周的第一天，然后继续添加1天并将副本推送到数组：

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function days(current) {
  var week = [];
  // Starting Monday not Sunday 
  var first = current.getDate() - current.getDay() + 1;
  current.setDate(first);
  for (var i = 0; i < 7; i++) {
    week.push(new Date(+current));
    current.setDate(current.getDate()+1);
  }
  return week;
}

var input = new Date(2017, 1, 27);
console.log('input: %s', input);

var result = days(input);
console.log(result.map(d => d.toString()));

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请注意，这会更改传入的日期（根据原始代码），您可能希望使当前副本以避免这种情况。

Answer 3

您可以使用Moment.js库 - 实用程序库进行日期/时间操作

以下是从星期一开始获取当前一周的日期的示例代码：

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function getThisWeekDates() {
  var weekDates= []; 

  for (var i = 1; i <= 7; i++) {
    weekDates.push(moment().day(i)); 
  }

  return weekDates; 
}

var thisWeekDates = getThisWeekDates();

thisWeekDates.forEach(function(date){ console.log(date.format());});

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<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.js"></script>

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上面的代码将以下结果打印到控制台：

2017-03-20T21:26:27+01:00
2017-03-21T21:26:27+01:00
2017-03-22T21:26:27+01:00
2017-03-23T21:26:27+01:00
2017-03-24T21:26:27+01:00
2017-03-25T21:26:27+01:00
2017-03-26T21:26:27+02:00

Answer 4

假设星期一从一周开始，您可以计算星期一并转到星期日。 getDate为您提供星期几，而星期日从0开始。有了momnday，我们可以向前偏移6天以获取星期天

mondayThisWeek(date: Date): Date {
  const d = new Date(date)
  const day = d.getDay()
  const diff = d.getDate() - day + (day === 0 ? -6 : 1)
  return new Date(d.setDate(diff))
}

const offsetDate = (base: Date, count: number): Date => {
  const date = new Date(base)
  date.setDate(base.getDate() + count)
  return date
}

thisWeek(today: Date): TimeRange {
  const monday = mondayThisWeek(today)
  return {
    startDate: monday,
    endDate: offsetDate(monday, 6)
  }
}

Answer 5

使用moment

即可轻松实现

const getWeekDates = () => {

  let weekDates = [];

  for (let i = 0; i < 7; i++)
    weekDates.push(moment().add(i, 'd'));

  return weekDates;
};


console.log(getWeekDates());

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.js"></script>