Sort array of objects by their numerical keys

Question

I'm trying to sort an array, where its objects consist of a dynamic key of type number.

Now I want to sort the objects so that the numbers start from the smallest first -- the number I mean is the key of the object.

Here's my code

const arr = [{"3": 32}, {"1": 42}, {"5": 48}];

arr.sort((a,b) => {
  if (a < b) {
    return -1;
  }

  if (a > b) {
    return 1;
  }

  return 0;
});

console.log(arr);

The order of the objects should be:

[{"1": 42},{"3":32},{"5":48}]

Does this answer your question? [Sort array of objects by string property value](https://stackoverflow.com/questions/1129216/sort-array-of-objects-by-string-property-value) — Sheri, Feb 17 '22 at 06:54
@Sheri No, that question is about sorting an array of objects by the _value_ of a fixed property, _lexicographically_. This question is about sorting an array of single-property objects by _key_, _numerically_. — Sebastian Simon, Feb 17 '22 at 07:00
Duplicate target found on [this search page](/search?page=2&tab=Relevance&q=is%3aa%20sort%20url%3a%22Object%2fkeys%22). — Sebastian Simon, Feb 17 '22 at 07:01

score 4 · Accepted Answer · answered Feb 17 '22 at 06:51

4

You'll need to extract the keys... like with Object.keys:

const arr = [{"3": 32}, {"1": 42}, {"5": 48}];

arr.sort((a,b) => Object.keys(a)[0] - Object.keys(b)[0]);

console.log(arr);

answered Feb 17 '22 at 06:51

trincot

317,000
35
244
286

Ridwan Ajibola · Answer 2 · 2022-02-17T10:39:55.763

1

use this and it should work

let arr = [{"3": 32}, {"1": 42}, {"5": 48}];

let getKey=(array)=> Object.keys(array)[0]

arr.sort((a,b) => (getKey(a) - getKey(b)))

console.log(arr)

edited Feb 17 '22 at 10:39

answered Feb 17 '22 at 06:53

Ridwan Ajibola

873
11
16

score 1 · Answer 3 · answered Feb 17 '22 at 06:54

1

This should work

const arr = [{"3": 32}, {"1": 42}, {"5": 48}];

arr.sort((a,b) => {
  const firstKey = Object.keys(a)[0]
  const secondKey = Object.keys(b)[0]
    return  secondKey - firstKey
})

answered Feb 17 '22 at 06:54

Ahmed Mansour

500
4
14

score 1 · Answer 4 · answered Feb 17 '22 at 06:54

Not sure whether its perfect, but surely works.

const arr = [{"3": 32}, {"1": 42}, {"5": 48}];

const sortedArr = arr.sort((a,b) => {
  let aKey = parseInt(Object.keys(a)[0]);
  let bKey = parseInt(Object.keys(b)[0]);

  return aKey - bKey;
});

console.log(sortedArr);

Sort array of objects by their numerical keys

4 Answers4