How to sort an object by date in keys in Javascript

Question

I have the following object:

var obj = { 2017-05-28: 76.16108625212159, 2017-02-12: 70.32183347555772, 2017-05-21: 74.21070693205216, 2017-04-23: 78.49819059107358, 2017-03-05: 73.36286201022146, 2017-04-02: 79.07588060050237, 2017-01-29: 79.07021235890568, 2017-03-26: 74.79360018220122, 2017-01-22: 71.80166785183269, 2017-04-09: 72.68569443640364 };

I would like to sort it by date, beginning from January, but I have no idea how to do this.

What do you think, is it possible in JS ?

Thanks in advance,

Please, copy your object and put it into the question. *You can use JSON.stringify(object)* to print it as string so you can copy it easily. — Mohamed Abbas, Jun 28 '17 at 11:36
Objects don't hold any order in Javascript, so first you need to convert it to an array. Then use [`array.sort()`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/sort) — Christopher Moore, Jun 28 '17 at 11:47
@john_js_py Converting the array back to an object loses any sorting you've just done. Keep it as an array if you want to access the sorted elements — Christopher Moore, Jun 28 '17 at 13:00

Prags · Answer 1 · 2017-06-28T12:03:57.307

1

var obj = '{ "2017-05-28": "76.16108625212159", "2017-02-12": "70.32183347555772", "2017-05-21": "74.21070693205216", "2017-04-23": "78.49819059107358", "2017-03-05": "73.36286201022146", "2017-04-02": "79.07588060050237", "2017-01-29": "79.07021235890568", "2017-03-26": "74.79360018220122", "2017-01-22": "71.80166785183269", "2017-04-09": "72.68569443640364" }';
pobject = JSON.parse(obj);
arr = Object.keys(pobject);
sorted = arr.sort();
len = sorted.length;
for(i=0;i<len;i++)
{
val= pobject[sorted[i]];
console.log(val);
}

This will work

Hope this helps..!

edited Jun 28 '17 at 12:03

answered Jun 28 '17 at 11:56

Prags

811
5
17

@john_js_py , this is done by using js native functions for sorting – Prags Jun 28 '17 at 11:58

score 1 · Accepted Answer · answered Jun 28 '17 at 11:56

The order of keys is not guaranteed in an object. you can convert your data structure into a sorted array as shown below and iterate over the array in order for your needs:

var obj = {
  "2017-05-28": 76.16108625212159,
  "2017-02-12": 70.32183347555772,
  "2017-05-21": 74.21070693205216,
  "2017-04-23": 78.49819059107358,
  "2017-03-05": 73.36286201022146,
  "2017-04-02": 79.07588060050237,
  "2017-01-29": 79.07021235890568,
  "2017-03-26": 74.79360018220122,
  "2017-01-22": 71.80166785183269,
  "2017-04-09": 72.68569443640364
};

var sortedArray = Object.keys(obj).sort().map(function(key) {
  return {
    date: key,
    value: obj[key]
  }
});

console.log(sortedArray);
/**Outputs:
[
  {
    "date": "2017-01-22",
    "value": 71.80166785183269
  },
  {
    "date": "2017-01-29",
    "value": 79.07021235890568
  },
  {
    "date": "2017-02-12",
    "value": 70.32183347555772
  },
  {
    "date": "2017-03-05",
    "value": 73.36286201022146
  },
  {
    "date": "2017-03-26",
    "value": 74.79360018220122
  },
  {
    "date": "2017-04-02",
    "value": 79.07588060050237
  },
  {
    "date": "2017-04-09",
    "value": 72.68569443640364
  },
  {
    "date": "2017-04-23",
    "value": 78.49819059107358
  },
  {
    "date": "2017-05-21",
    "value": 74.21070693205216
  },
  {
    "date": "2017-05-28",
    "value": 76.16108625212159
  }
]
**/

Mohamed Abbas · Answer 3 · 2017-06-28T12:04:59.463

Using Array.prototype.sort() and Array.prototype.reduce()

You can not order object proprieties. so you may need to convert your object to an array

Example

var obj = {
        "2017-05-28": 76.16108625212159,
        "2017-02-12": 70.32183347555772,
        "2017-05-21": 74.21070693205216,
        "2017-04-23": 78.49819059107358,
        "2017-03-05": 73.36286201022146,
        "2017-04-02": 79.07588060050237,
        "2017-01-29": 79.07021235890568,
        "2017-03-26": 74.79360018220122,
        "2017-01-22": 71.80166785183269,
        "2017-04-09": 72.68569443640364
    },

    sortedArr = Object.keys(obj)
        .sort(function (a, b) { 
            return new Date(a) - new Date(b)
         })
        .reduce(function (acc, item, index) {
            acc.push({
                date: item,
                value: obj[item]
            });
            return acc;
        }, []);
    console.log(sortedArr);

Thanks @Shivam for your note

Though this would give out the object with keys ordered, But that is not guaranteed, More about it [here](https://stackoverflow.com/questions/5525795/does-javascript-guarantee-object-property-order) — Shivam, Jun 28 '17 at 11:55

How to sort an object by date in keys in Javascript

3 Answers3