Question

我正在处理与日志和时间相关的应用程序。我有这个数组与对象（日志）。我想找到最接近现在的checkin_time（来自对象的属性）的对象。所以，如果我有两个对象，一个来自＆＃34; 2018-04-05 08：04：12＆＃34; ＆＃34; 2018-04-05 10：02：12＆＃34;我想找到对象＆＃34; 2018-04-05 10：02：12＆＃34;因为那是从现在起最近的时间。

我尝试使用Moment.js库，但这并没有成功。我正在使用Vue框架。

更新

我已经尝试过下面的一个答案，但我仍然未定义。有什么东西我不明白吗？

代码

checkin_time

Answer 1

有关详细信息，请参阅Map，Math.min()和Math.abs()。

＆＃13;

// Input.
const input = [
  {id: 1, checkin_time: "2030-05-05 16:22:02"}, // 4 PM MAY 5 2030. 
  {id: 2, checkin_time: "2030-05-05 08:22:02"}, // 8 AM MAY 5 2030.
  {id: 3, checkin_time: "2000-05-05 13:22:02"}, // 1 PM MAY 5 2030.
  {id: 4, checkin_time: "2000-05-05 11:22:02"}, // 11 AM MAY 5 2030.
]

// Is Before Now
const isBeforeNow = x => (Date.now() > x)

// Generate Key.
const generateKey = x => Math.abs(Date.now()*1 - x*1)

// Closest From Now.
const closestFromNow = (times, restriction) => {

  const m = new Map(times.map(x => {
  
    let date = new Date(x.checkin_time)
     
    if (restriction == 'before') {
      if (isBeforeNow(date)) date = generateKey(date)
      else date = undefined
    }
    
    else if (restriction == 'after') {
      if (!isBeforeNow(date)) date = generateKey(date)
      else date = undefined
    }
    
    else {
      date = generateKey(date)
    }
    
    return [date, x]
    
  }))
  
  m.delete(undefined)
  
  return m.get(Math.min(...m.keys()))
}

// Proof.
console.log('Closest Before Now', closestFromNow(input, 'before')) // ID 3.
console.log('Closest After Now', closestFromNow(input, 'after')) // ID 2.
console.log('Closest From Now In General 1', closestFromNow(input)) // ID 3.
console.log('Closet From Now In Generate 2', closestFromNow([...input, {id: 11, checkin_time: "2020-05-05 11:22:02"}])) // ID 11.

＆＃13;

Answer 2

methods: {
    getLog() {

        var bigestElem = null;
        var closestTime  = 0;
        var elemTime = 0;
        this.users.forEach(element => {

            element.logs.forEach((log) => {
              elemTime =  new Date(log.checkin_time).getTime()
              if(log.finished === false && elemTime > closestTime){
                closestTime = elemTime;
                bigestElem = log;
              }
                this.Logs.push(log);

            })

        });
        console.log(bigestElem);
        return bigestElem
      



    }
},

Answer 3

您可以创建一个辅助函数：

const input = [
  {id: 1, checkin_time: "2030-05-05 10:22:02"}, // 10 AM. 
  {id: 2, checkin_time: "2030-05-05 08:22:02"} // 8 AM.
]


function findNearestTime(times){
  let currentTime = Date.now();
  let diff = times.map(time => {
    return Math.abs(currentTime - Date.parse(time.checkin_time));
  })

  let i = diff.indexOf(Math.min(...diff));

  return times[i].checkin_time;
}

let latest = findNearestTime(input);
alert("nearest time is :" + latest)

以下是working fiddle

参考：Date.now()和Date.parse()

返回项目，距离现在最近的时间是JavaScript / Moment.js

3 个答案: