CODEWITHSUNDEEP
javascriptarrayssorting
Diamonds
Diamonds

Reputation: 117

Can't sort array containing int

I'm unable to sort an array containing int. Here's my code for the sort :

var asr = [];

function sortNumber(a, b) {
  return b - a;
}
asr.sort(sortNumber);

The function sort doesn't do anything, here is a sample of my array when I made a console.log(asr) on chrome :

by: 3
de: 2
ds: 14
sr: 2
vi: 1

proto: Array(0)

Upvotes: 0

Views: 92

Answers (3)

Rubén Morales Félix
Rubén Morales Félix

Reputation: 652

Properties in arrays remain in the order that you define them, if you want to have them sorted then you need to define them sorted from the beginning, that being said you can get all the properties of your array, sort the values for this properties from your array and insert this sorted properties into a new array.

const asr = []; 

asr.by = 3; 
asr.de = 2; 
asr.ds = 14;
asr.sr = 2;
asr.vi = 1;

function sortNumber(a, b) {
  return b - a;
}

let asr2 = [...asr];

Object.keys(asr)
    .map(key => ({ key, value: asr[key] }))
    .sort((a, b) => b.value - a.value)
    .forEach(a => asr2[a.key] = a.value);


console.log(asr2)

/* 
  // if asr contains values and you also 
  // want to sort those values you need 
  // to sort them separately

  asr2 = asr2.sort((a, b) => b - a)
  console.log(asr2)
*/

If what you what is to keep the properties in the same position but sort only the values then try this

const asr = []; 

asr.by = 3; 
asr.de = 2; 
asr.ds = 14;
asr.sr = 2;
asr.vi = 1;

function sortNumber(a, b) {
  return b - a;
}

const asrKeys = Object.keys(asr);

const asrSortedValues =  asrKeys.map(key => asr[key])
                          .sort((a, b) => b - a);

asrKeys.forEach((key, index) => asr[key] = asrSortedValues[index]);


console.log(asr)

Upvotes: 0

tex
tex

Reputation: 2766

Based on your recent update, it seems asr is an array with properties you've added. That's not generally a good idea unless you know what you're doing, and sort() won't touch those properties.

Instead, I would use a normal object, with the caveat that objects in JavaScript aren't really meant to contain an ordered collection of values. With that caveat out of the way, this is how I'd store the data, and how I'd sort the keys:

const asr = {by: 3, ds: 14, de: 2, vi: 1, sr: 2}

console.log(
Object.fromEntries(
  Object.entries(asr).sort(
    ([ak, av], [bk, bv]) => av > bv ? 1 : -1
  )
)
)

I'll keep the rest here, even though it isn't relevant to your question.

asr is most likely an array of objects, in which case asr.sort() has sorted the array by the result of the contained objects' toString method:

const asr = [{vi: 1}, {sr: 2}, {by: 3}, {ds: 14}, {de: 2}]

console.log(asr.sort())

If you want to sort it by object values, this will do the trick:

const asr = [{vi: 1}, {sr: 2}, {by: 3}, {ds: 14}, {de: 2}]

console.log(asr.sort(
  (a, b) => Object.values(a)[0] > Object.values(b)[0] ? 1 : -1
))

If you want to sort by object keys, this should work:

const asr = [{vi: 1}, {sr: 2}, {by: 3}, {ds: 14}, {de: 2}]

console.log(asr.sort(
  (a, b) => Object.keys(a)[0] > Object.keys(b)[0] ? 1 : -1
))

Upvotes: 3

mottek
mottek

Reputation: 957

Your sort function is correct, check with: console.log([51,2,13,4,5].sort(function(a,b) {return b-a}));

asr doesn't seem to be an array but an object.

Upvotes: 0

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