Question

我有两个数组

var events=["DELIVERED", "OUT TO DELEVERY", "REACHED WAREHOUSE", "DEPARTED"];

var eventDetails= [{
"source" : "application"
"DateTime": "2016-05-12 11:20:00",
"eventName" : "DELIVERED"
},
{
"source" : "application"
"DateTime": "2017-06-07 00:00:00",
"eventName" : "OUT TO DELEVERY"
},
{
"source" : "application"
"DateTime": "2016-11-05 11:20:00",
"eventNname" : "CUSTOM CLEARANCE"
}];

如果最新的eventName出现在“events”数组中，我需要从eventDetails数组中显示最新的eventName（最新的日期和时间）。否则它应该返回null（如果最新更新记录中的eventName不包含事件数组中的任何值）。

Answer 1

您可以通过几种不同的方式完成此操作。一个简单的解决方案是按日期排序事件，然后抓住你需要的那个（在这种情况下是第一个）：

var eventDetails= [{
  "source" : "application",
  "DateTime": "2016-05-12 11:20:00",
  "eventName" : "DELIVERED"
}, {
  "source" : "application",
  "DateTime": "2017-06-07 00:00:00",
  "eventName" : "OUT TO DELEVERY"
}, {
  "source" : "application",
  "DateTime": "2016-11-05 11:20:00",
  "eventNname" : "CUSTOM CLEARANCE"
}];

var last = eventDetails.sort(function(prev, next) {
    return new Date(next.DateTime) - new Date(prev.DateTime);
})[0];

var lastEventName = last.eventName;

if (events.indexOf(lastEventName) >= 0) {
  // Return true
} else {
  // Return false
}

选项2：

您还可以循环浏览所有事件并跟踪最新事件：

var last = eventDetails[0];
for (var i = 1; i < eventDetails.length; i++) {
  if (eventDetails[i].DateTime > last.DateTime) {
    last = eventDetails[i];
  }
}
var lastEventName = last.eventName;

if (events.indexOf(lastEventName) >= 0) {
  // Return true
} else {
  // Return false
}

Answer 2

您可以使用javascript sort方法并使用indexOf检查events数组中是否存在值

var events=["DELIVERED", "REACHED WAREHOUSE", "OUT TO DELEVERY", "DEPARTED"];

var eventDetails= [{
"source" : "application",
"DateTime": "2016-05-12 11:20:00",
"eventName" : "DELIVERED"
},
{
"source" : "application",
"DateTime": "2017-06-07 00:00:00",
"eventName" : "OUT TO DELEVERY"
},
{
"source" : "application",
"DateTime": "2016-11-05 11:20:00",
"eventName" : "CUSTOM CLEARANCE"
}];

eventDetails = eventDetails.sort(function(a,b){
  return new Date(b.DateTime) - new Date(a.DateTime)
})
 
if( events.indexOf(eventDetails[0].eventName) !== -1 ){ 
  console.log('true')
}else{
 console.log('false')
}

如何检索最新的eventName（按日期最新）

2 个答案:

选项2：