如何根据日期过滤数据？

Question

我有一个数组，

var data = [
    { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
    { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
    { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
    { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
    { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
    { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" }
    ];
    
    
data.forEach(function(result) {
   console.log(result.jobCategoryWithFromDate);
});

在控制台中给出上述结果..

在 foreach 中，我需要返回具有最新日期的 jobCategoryWithFromDate。

所以预期的结果是，（下同）..

ASSIST.. / Assistance [valid from 2019-01-01]
PROF.. / Professional [valid from 2019-01-01]
SEN.. / Senior [valid from 2019-01-01]

以上是预期的结果，没有任何变化，只需要过滤结果并返回jobCategoryWithFromDate返回具有最新日期的唯一值..

尽管名称重复，但过滤器需要根据日期（最新）处理..

编辑：

我已经接受了答案，但后来我才知道它在所有情况下都不起作用，很抱歉没有完全测试它..

不知道我的解释是否出错，但如果用户名相同，则需要根据日期进行过滤，否则需要显示具有任何日期的唯一用户。

例如：

    var data = [
        { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
        { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
        { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
        { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
        { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
        { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
        { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
        { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
        { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" },
        { id: 10, jobCategoryWithFromDate: "Jun.. / Junior  [valid from 2018-01-01]" },
        { id: 11, jobCategoryWithFromDate: "Usr.. / User [valid from 2019-01-01]" },
        { id: 12, jobCategoryWithFromDate: "Man.. / Manager [valid from 2017-05-01]" }
    ];

function extractDate(string){
  return string.match(/[0-9]+-[0-9]+-[0-9]+/g);
}

var result = data.reduce((newestDates, currentItem)=>{
  if (newestDates.length===0) newestDates.push(currentItem);
  else {
    const dateDifference = new Date(extractDate(newestDates[0].jobCategoryWithFromDate)) - new Date(extractDate(currentItem.jobCategoryWithFromDate));
    
    if (dateDifference===0) newestDates.push(currentItem); // push items with the same date as newest found
    else if (dateDifference <= 0) newestDates = [currentItem]; // if item has newer date the original array gets replaced with one containing just this item
    // ignore case dateDifference >= 0 because we do not need to do anything with dates older than the newest found
  }
  return newestDates;
},[]);

console.log(result);

在此 sn-p 中查看最后三个值，它们的用户名不同，但与以前的记录具有相同的日期..

这里的预期结果是我需要获取所有最后三个记录以及以上三个记录，因为它们是不同的用户，比如

ASSIST.. / Assistance [valid from 2019-01-01]
PROF.. / Professional [valid from 2019-01-01]
SEN.. / Senior [valid from 2019-01-01]
Jun.. / Junior  [valid from 2018-01-01]
Usr.. / User [valid from 2019-01-01]
Man.. / Manager [valid from 2017-05-01]

Answer 1

假设日期格式为YYYY-MM-DD，您只需从每个元素中提取包含日期的部分字符串并从中创建日期对象

编辑：似乎您想要的是获取每个用户的最后日期，而不是只获取具有最新日期的条目数组，编辑 sn-p 以匹配它（您可以如果您想要不同的比较来区分用户，请编辑提取名称的正则表达式的一部分）

var data = [
    { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
    { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
    { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
    { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
    { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
    { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" },
    { id: 10, jobCategoryWithFromDate: "Jun.. / Junior  [valid from 2018-01-01]" },
    { id: 11, jobCategoryWithFromDate: "Usr.. / User [valid from 2019-01-01]" },
    { id: 12, jobCategoryWithFromDate: "Man.. / Manager [valid from 2017-05-01]" }
];
    
function extractNameNDate(string){
  return [string.match(/^\w+/), string.match(/[0-9]+-[0-9]+-[0-9]+/g)];
}

var result = data.reduce((newestDates, currentItem)=>{
  const [user, date] = extractNameNDate(currentItem.jobCategoryWithFromDate);
  if (newestDates[user]) {
    // compare dates for given user
    const [storedUser, storedDate] = extractNameNDate(newestDates[user].jobCategoryWithFromDate);
    const dateDifference = new Date(storedDate) - new Date(date);
    
    if (dateDifference <= 0) newestDates[user] = currentItem;
    
  } else {
    newestDates[user]=currentItem;
  }
  return newestDates;
},{});

result = Object.values(result);

console.log(result);

这是一个经过编辑的版本，用于匹配字符串的整个第一部分，直到 [] 大括号

var data = [
    { id: 1, jobCategoryWithFromDate: "01-05 Data Specialist [valid from 2019-01-01]" },
    { id: 2, jobCategoryWithFromDate: "01-05 Support [valid from 2019-01-01]" },
    { id: 3, jobCategoryWithFromDate: "03-04 Technician [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "05 Engineer [valid from 2019-01-01]" },
    { id: 5, jobCategoryWithFromDate: "05 Technician [valid from 2019-01-01]" },
    { id: 6, jobCategoryWithFromDate: "05 Technologist [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "06 Engineer [valid from 2019-01-01]" },
    { id: 8, jobCategoryWithFromDate: "06-07 Sr. Technician [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "Intern [valid from 2019-01-01]" },
    { id: 10, jobCategoryWithFromDate: "06-07 Support  [valid from 2019-01-01]" },
    { id: 11, jobCategoryWithFromDate: "06-07 Technologist [valid from 2019-01-01]" },
    { id: 12, jobCategoryWithFromDate: "07 Engineer [valid from 2019-01-01]" },
    { id: 13, jobCategoryWithFromDate: "08 Senior [valid from 2019-01-01]" },
    { id: 14, jobCategoryWithFromDate: "08-09 Support [valid from 2019-01-01]" },
    { id: 15, jobCategoryWithFromDate: "09 Senior [valid from 2019-01-01]" },
    { id: 16, jobCategoryWithFromDate: "10-11 Principal [valid from 2019-01-01]" },
    { id: 17, jobCategoryWithFromDate: "12-13 Sr. Principal [valid from 2019-01-01]" },
    { id: 18, jobCategoryWithFromDate: "14 Vice President [valid from 2019-01-01]" },
    { id: 19, jobCategoryWithFromDate: "15 President [valid from 2019-01-01]" }
];
    
function extractNameNDate(string){
  return [string.match(/[^\/]*/), string.match(/[0-9]+-[0-9]+-[0-9]+/g)];
}

var result = data.reduce((newestDates, currentItem)=>{
  const [user, date] = extractNameNDate(currentItem.jobCategoryWithFromDate);
  if (newestDates[user]) {
    // compare dates for given user
    const [storedUser, storedDate] = extractNameNDate(newestDates[user].jobCategoryWithFromDate);
    const dateDifference = new Date(storedDate) - new Date(date);
    
    if (dateDifference <= 0) newestDates[user] = currentItem;
    
  } else {
    newestDates[user]=currentItem;
  }
  return newestDates;
},{});

result = Object.values(result);

console.log(result);

Answer 2

我会先找到最新的日期，然后在数组中过滤具有该日期的对象。这将只返回日期最高的对象：

var data = [
  { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
  { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
  { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
  { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
  { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
  { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
  { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
  { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
  { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" }
];

/* Add new property to data objects to store the "valid from" timestamp - Avoids parsing the text twice */
data.forEach(function(element, index, array) {
  var dateText = element.jobCategoryWithFromDate.match(/\[valid from (\d{4}-\d{2}-\d{2})\]$/)[1];
  array[index].fromDateTimestamp = +(new Date(dateText));
});

/* Get the highest value (the latest date) */
var max = data.reduce(function(currentMax, value) {
  return Math.max(currentMax, value.fromDateTimestamp);
}, 0);

/* Filter the data array to only include objects with the latest date */
var newData = data.filter(function(value) {
  return value.fromDateTimestamp === max;
});

console.log(newData);

Answer 3

您可以应用正则表达式从字符串jobCategoryWithFromDate 中提取日期。然后按日期排序，你会得到最新的结果。

var data = [
    { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
    { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
    { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
    { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
    { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
    { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" }
    ];

var result= data.map(d => ({...d, date: d.jobCategoryWithFromDate.match(/(\d{1,4}([.\-/])\d{1,2}([.\-/])\d{1,4})/g)[0]}))..sort((a, b)=> new Date(b.date) - new Date(a.date))

console.log(result)

Answer 4

你可以使用一个简单的 reduce 来做到这一点， 您可以通过存储数组和 currentMaxDateTS 来改进减少，而不是在每次迭代中重新计算时间戳。

如果您需要有关此代码 sn-p 的更多解释，请不要犹豫

const data = [
    { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
    { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
    { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
    { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
    { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
    { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" }
    ];

// Function returning the date string inside  [valid from 2017-05-01]
const getDateFromJobCategory = (jobCategoryWithFromDate) =>  jobCategoryWithFromDate.match(/[0-9]+-[0-9]+-[0-9]+/g);


const filteredData = data.reduce((acc, data) => {
  // Get data date in timestamp
  const dataDateString = getDateFromJobCategory(data.jobCategoryWithFromDate);
  const dataDateTS = new Date(dataDateString).getTime();
  // Get current max date in timestamp
  const currentMaxDate = getDateFromJobCategory(acc[0]);
  const currentMaxDateTS = new Date(currentMaxDate).getTime()

  return dataDateTS > currentMaxDateTS ? [data.jobCategoryWithFromDate] : dataDateTS === currentMaxDateTS ? [...acc, data.jobCategoryWithFromDate] : acc

}, ["[valid from 0001-01-01]"]);

   const finalResult = filteredData.forEach(jobCategoryWithFromDate => 
   console.log(jobCategoryWithFromDate))

Answer 5

您可以通过使用正则表达式提取日期来使用简单的排序，然后使用递归函数检查是否有多个相同的日期：

var data = [
    { id: 1, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2017-05-01]" },
    { id: 2, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2018-01-01]" },
    { id: 3, jobCategoryWithFromDate: "ASSIST.. / Assistance [valid from 2019-01-01]" },
    { id: 4, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2017-05-01]" },
    { id: 5, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2018-01-01]" },
    { id: 6, jobCategoryWithFromDate: "PROF.. / Professional [valid from 2019-01-01]" },
    { id: 7, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2018-01-01]" },
    { id: 8, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2019-01-01]" },
    { id: 9, jobCategoryWithFromDate: "SEN.. / Senior [valid from 2017-05-01]" }
];

const getDate = date => +date.match(/[0-9]{4}-[0-9]{2}-[0-9]{2}/g)[0].split('-').join('')

data = data.sort(({jobCategoryWithFromDate:date1}, {jobCategoryWithFromDate:date2}) => getDate(date2) - getDate(date1))

const getRecent = (data, i=0) => getDate(data[i].jobCategoryWithFromDate) === getDate(data[i + 1].jobCategoryWithFromDate) ? [data[i], ...getRecent(data, i+1)] : [data[i]]

getRecent(data).forEach(obj => console.log(obj))