Question

我需要一些JavaScript代码帮助，如果第二个日期大于3天，我需要检查两个字符串日期值（firstDate和secondDate），我正在以字符串格式mm / dd / yyyy获取这些值。请帮忙。

   var firstDate = '10/01/2019'
   var secondDate = '10/04/2019' 

  if ((inputData.firstDate)+3 === inputData.secondDate) {
    //return []; //
    return {dateCheck: 'Not greater than 3 days'};
  }
  else
  {
    return {dateCheck: 'Greater than 3 days'};
  }

Answer 1

要将N天添加到您使用的日期Date.getDate() + N

var d1 = new Date('10/01/2019');
var d2 = new Date('10/04/2019');
var isGreater = +d2 > d1.setDate(d1.getDate() + 3); // false (equals three days)

鉴于以上所述，您可以创建一个简单的可重用功能

/**
 * Check if d2 is greater than d1
 * @param {String|Object} d1 Datestring or Date object
 * @param {String|Object} d2 Datestring or Date object
 * @param {Number} days Optional number of days to add to d1
 */
function isDateGreater (d1, d2, days) {
  d1 = new Date(d1);
  return +new Date(d2) > d1.setDate(d1.getDate() + (days||0))
}

console.log(isDateGreater('10/01/2019', '10/03/2019', 3)); // false (smaller)
console.log(isDateGreater('10/01/2019', '10/04/2019', 3)); // false (equal)
console.log(isDateGreater('10/01/2019', '10/05/2019', 3)); // true (greater than)
// Without the optional third parameter
console.log(isDateGreater('10/01/2019', '10/05/2019')); // true (is greater date)

回顾一下：创建一个函数，在将N天添加到日期后，计算两个时间戳。

Date.setDate ^_MDN
Date.getDate ^_MDN

Answer 2

也许您可以定义一个辅助函数来解析您输入的日期字符串，以便您可以像下面这样对3天的偏移量进行每个日期之间的比较：

var firstDate = '10/01/2019'
var secondDate = '10/04/2019'

/*
Define helper function to parse input date string and
return the date as milliseconds since epoch time, whihch
gives us an easy format to compare offset dates
*/
function parseDate(str) {
  
  /*
  Break input string into date parts
  */
  const parts = str.split('/').map(p => parseInt(p));
  
  /*
  Create date object and populate parts
  */
  const date = new Date();
  date.setTime(0);
  date.setDate(parts[0]);
  date.setMonth(parts[1] - 1);
  date.setFullYear(parts[2]);

  /*
  Return date in milliseconds
  */
  return date.getTime()
}

/*
If first input date + 3 days (in milliseconds) is less than second input
date, then second date is not greater than 3 days since first date
*/
if (parseDate(firstDate) + (86400000 * 3) < parseDate(secondDate)) {
  console.log('Not greater than 3 days');
} else {
  console.log('Greater than 3 days');
}

Answer 3

我已将其包含在函数中，以便您进行测试。

在这里我们正在检查（（date1-date2）<259200000）（Unix时间戳中的3天）

function isItGreaterThan(date1, date2) {
  var firstDate = new Date(date1);
  var secondDate = new Date(date2);
  if ((secondDate.getTime() - firstDate.getTime()) < 259200000) {
    console.log({dateCheck: 'Not greater than 3 days'});
  } else {
    console.log({dateCheck: 'Greater than 3 days'});
  }
}

isItGreaterThan('10/01/2019', '10/02/2019');
isItGreaterThan('10/01/2019', '10/03/2019');
isItGreaterThan('10/01/2019', '10/04/2019');

Answer 4

从第二个日期起减去3天，并检查是否仍大于第一个日期。

var firstDate = '10/01/2019';
var secondDate = '10/04/2019';
var thirdDate =  '11/01/2019'; // this is to test.

const pastThreeDays = (firstDate, secondDate) => {
  // Time is measured in milliseconds, so lets create a variable for a day.
  const day = 1000 * 60 * 60 * 24;
  let fDate = new Date(firstDate);
  let sDate = new Date(secondDate);
  sDate = new Date(sDate.getTime() - (3 * day));
  console.log(`${fDate} - ${sDate}`);
  // If sDate is still greater than fDate after subtracting 3 days then we are past three days.
  return fDate.getDate() < sDate.getDate();
};

console.log(pastThreeDays(firstDate, secondDate));
console.log(pastThreeDays(firstDate, thirdDate));

Answer 5

对于许多不同的Date用法，我建议使用dateFns。 DateFns是日期对象JS库，具有许多date操作可用的方法。参考：DateFns

您还可以使用库中的format以不同的格式设置日期

为此，我建议使用addDays中的dateFns方法

const secondDate = '04/04/2019',
firstDate = '04/01/2019'

alert(new Date(secondDate) >= dateFns.addDays(new Date(firstDate), 3))

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/date-fns/1.30.1/date_fns.min.js"></script>

检查日期字符串是否大于3天

5 个答案: