根据日期对一组JavaScript对象进行排序

Question

i have that file json:

var Point = [{

"id": 1,
"name": "A",
"LastUpdate": "2016-07-08",
"position": [36.8479648, 10.2793332]},{
"id": 1,
"name": "A",
"LastUpdate": "2016-07-07",
"position":[ 36.8791039, 10.2656209]},{
"id": 1,
"name": "A",
"LastUpdate": "2016-07-09",
"position": [36.9922751, 10.1255164]},{
"id": 1,
"name": "A",
"LastUpdate": "2016-07-10",
"position": [36.9009882, 10.3009531]},{
"id": 1,
"name": "A",
"LastUpdate": "2016-07-04",
"position": [37.2732415, 9.8713665]}];

How can i sort the objects by the LastUpdate(it's a date) property in ascending and descending order using only JavaScript?

Answer 1

Try like this

Point.sort(function(a, b) {
  return (new Date(b.LastUpdate)) - (new Date(a.LastUpdate))
})

DEMO

Answer 2

As your date format is YYYY-MM-DD ( year, followed by month, followed by date ), you can simply compare them as strings using String's localeCompare() method.

Then, you just need to add this to your custom sort function as described below:

 var Points = [{ "id": 1, "name": "A", "LastUpdate": "2016-07-08", "position": [36.8479648, 10.2793332]},{ "id": 1, "name": "A", "LastUpdate": "2016-07-07", "position":[ 36.8791039, 10.2656209]},{ "id": 1, "name": "A", "LastUpdate": "2016-07-09", "position": [36.9922751, 10.1255164]},{ "id": 1, "name": "A", "LastUpdate": "2016-07-10", "position": [36.9009882, 10.3009531]},{ "id": 1, "name": "A", "LastUpdate": "2016-07-04", "position": [37.2732415, 9.8713665]}]; Points.sort(function(a, b){ return a.LastUpdate.localeCompare( b.LastUpdate ); }); console.log( Points ); 

Answer 3

As string are in ISO format, they can be sorted by direct string comparison, so no need to convert them in different type of object.

As pointed by Nina in comments, chrome uses different sorting algorithm for arrays larger than 10, so after all the benchmark test, the best method to sort will be

1st in performance (Avg. ms per task 0.011690500000258907)

Point.sort(function(a,b) {
return (a.LastUpdate > b.LastUpdate) ? 1 : ((b.LastUpdate > a.LastUpdate) ?-1:0);
});

Than 2nd in performance (Avg. ms per task 0.029657999999879395)

Point.sort(function(a, b) {
  return a.LastUpdate.localeCompare( b.LastUpdate );
})

3rd in performance (Avg. ms per task 0.03225850000019418)

Point.sort(function(a, b) {
  return (new Date(b.LastUpdate)) - (new Date(a.LastUpdate))
})

Answer 4

You can use the sort function with a compare function.

Point.sort(function(a, b) {
    var aSplit = a.LastUpdate.split("-"),
        aDate = new Date(aSplit[2], aSplit[1], aSplit[0]),
        bSplit = b.LastUpdate.split("-"),
        bDate = new Date(bSplit [2], bSplit [1], bSplit [0]);

    return aDate - bDate;
});

Answer 5

Simple solution using Array.sort (with ES6 "arrow" function) and Date.parse function:

// ascending order
Point.sort((a, b) => Date.parse(a.LastUpdate) - Date.parse(b.LastUpdate));

Answer 6

ascending and descending :

ascPoint = Point.sort((a,b) => Date.parse(a.LastUpdate) -Date.parse(b.LastUpdate));
descPoint = ascPoint.reverse();