排序并将空值添加到数组如果需要

  • Z时代
  • 2024-01-10
  • 分类：问答

我有一个数组，我要计数和排序。我怎样才能做到这一点？我的尝试会导致无限循环。排序并将空值添加到数组如果需要

我想这个数组

[ 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-05", timestamp: "2017-12-05 15:58:25", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-06 10:13:12", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-07 09:38:12", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-08", timestamp: "2017-12-08 09:35:25", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-11", timestamp: "2017-12-11 11:25:31", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-12", timestamp: "2017-12-12 15:05:17", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-13", timestamp: "2017-12-13 11:08:40", …} 
{activityId: 201609011024550000, Employee_employeeId: 100, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-15 11:51:33", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-18", timestamp: "2017-12-18 11:04:56", …} 
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-18 12:04:56", …} 
]

看起来像基于此阵/排序上Date_date

（Date_date： “2017年12月1日” 不存在，所以值是0， Date_date：“2017-12-06”存在两次，因此值为2）

[0,0,0,0...,1,2,0,1...]

好的，如果新建数组已创建。没有jquery。

编辑： 对不起，这里是循环不停止

for(var i = 0; i < a.length; i++){ 
    for(var j = 0; j <= b.length; j++){ 
     if(parseInt(a[i].Date_date.substring(8))-1==j){ 
      var num = b[j]; 
      b[j] = num+1; 
     } 
     else{ 
      var num = b[j]; 
      b[j] = num+0; 
     } 
    } 
}

回答：

首先排序阵列上日期，然后创建一个对象，查找基于Date_date。然后从排序后的数组中获取第一个和最后一个日期，并为该月的第一天和该月的最后一天创建日期对象。然后使用while循环，通过检查对象查找添加记录直到最后一个日期。

var data = [{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-05", timestamp: "2017-12-05 15:58:25"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-06 10:13:12"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-07 09:38:12"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-08", timestamp: "2017-12-08 09:35:25"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-11", timestamp: "2017-12-11 11:25:31"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-12", timestamp: "2017-12-12 15:05:17"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-13", timestamp: "2017-12-13 11:08:40"},{activityId: 201609011024550000, Employee_employeeId: 100, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-15 11:51:33"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-18", timestamp: "2017-12-18 11:04:56"},{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-18 12:04:56"},];  
var dateCount = data  
    .sort((a,b) => new Date(a.Date_date) - new Date(b.Date_date))  
    .reduce((r, o) => {  
     r[o.Date_date] = r[o.Date_date] || [];  
     r[o.Date_date].push(o)  
     return r;  
    }, {});  
//Get the first date from the sorted array  
var date1 = new Date(data[0].Date_date);  
var firstDay = new Date(date1.getFullYear(), date1.getMonth(), 2);  
//Get the last date from the sorted array  
var date2 = new Date(data[data.length - 1].Date_date);  
var lastDay = new Date(date2.getFullYear(), date2.getMonth() + 1, 1);  
var result = [];  
while(firstDay <= lastDay){  
    var count = (dateCount[firstDay.toISOString().split('T')[0]] || []).length;  
    result.push(count);  
    firstDay.setDate(firstDay.getDate() + 1);  
}  
console.log(result);

回答：

首先我试过的代码，你需要得到每个日期出现在一个阵列的次数。所以我使用data.forEach迭代了数组中的每个对象。

请注意，我正在跟踪名为counter的对象中的日期计数。

然后，我使用data.map将阵列中的每个对象映射到新阵列中的项目。因此，对于data阵列中的每个项目，我都会返回观察次数。

如果你不熟悉Array#map和Array#forEach，你可以阅读更多。

var data = [  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-05", timestamp: "2017-12-05 15:58:25"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-06 10:13:12"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-06", timestamp: "2017-12-07 09:38:12"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-08", timestamp: "2017-12-08 09:35:25"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-11", timestamp: "2017-12-11 11:25:31"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-12", timestamp: "2017-12-12 15:05:17"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-13", timestamp: "2017-12-13 11:08:40"},  
{activityId: 201609011024550000, Employee_employeeId: 100, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-15 11:51:33"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-18", timestamp: "2017-12-18 11:04:56"},  
{activityId: 201609011024550000, Employee_employeeId: 4075, projectId: 300000000000000200, Date_date: "2017-12-15", timestamp: "2017-12-18 12:04:56"}  
];  
var counter = {};  
data.forEach(function(item) {  
    var date = item.Date_date;  
    if(!!counter[date]) {  
    counter[date]++;  
    } else {  
    counter[date] = 1;  
    }  
});  
console.log("Date-wise counts: ", counter);  
var result = data.map(function(item) {  
    return counter[item.Date_date];  
});  
console.log("Result:", result);

以上是 排序并将空值添加到数组如果需要 的全部内容， 来源链接： utcz.com/qa/263839.html

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