Sort Javascript array of objects in place by property value with save keys

Question

How to sort array of objects by property 'cost' with holding string keys?

Start array :

aparts: {
    apart1 : {id: "1", status: 2, cost: 10033450},
    apart2 : {id: "2", status: 2, cost: 5214000},
    apart3 : {id: "3", status: 2, cost: 7314300},
    apart4 : {id: "4", status: 1, cost: 9261700}    
}

Want to array:

aparts: {
    apart2 : {id: "2", status: 2, cost: 5214000},
    apart3 : {id: "3", status: 2, cost: 7314300},
    apart4 : {id: "4", status: 1, cost: 9261700},
    apart1 : {id: "1", status: 2, cost: 10033450}   
}

well these are json objects, not arrays. If you can also work with arrays then you could use libraries like lodash or alasql — jetblack, Sep 19 '17 at 20:52
@DuncanThacker - have you actually looked at the desired result? — PM 77-1, Sep 19 '17 at 20:53
Sorting is an "arrays only" job... You best place your objects in an array and then sort them happily. — Redu, Sep 19 '17 at 20:56
@dsb do you actually mean arrays or objects? If you mean objects, there's no answer. — Duncan Thacker, Sep 19 '17 at 20:56
As @Redu says sorting is for arrays, this can be solved using reflection and iterating over the keys, placing them on an array, sorting the array and rebuilding the object. But i don't understand why is needed — Alberto, Sep 19 '17 at 21:00
@Redu thanks, try to do it. Sorry for question - your recommedation to improve knowledges of js ? — krolovolk, Sep 19 '17 at 21:01
The order of properties in an object is not defined. So there is no point in even trying to rearrange them. What are you actually trying to accomplish? — Matt Burland, Sep 19 '17 at 21:01
@Alberto i have this incoming json and have to sort data by property to display in the required order — krolovolk, Sep 19 '17 at 21:04
@dsb please answer Matt Burland question. There is no point on doing it — Alberto, Sep 19 '17 at 21:07
@MattBurland i have this incoming json and have to display data in Html in the required order (insert in divs, eg) — krolovolk, Sep 19 '17 at 21:10
@dsb then it sounds like you need to transform it into an array. Something that actually is ordered — Matt Burland, Sep 19 '17 at 21:10
Like everyone say an array is really want you need, something like -> `Object.keys(aparts).map((k) => {return {[k]:aparts[k]}}).sort((a,b) => a.cost - b.cost)` will transform into a sorted array. — Keith, Sep 19 '17 at 21:13

score 2 · Accepted Answer · answered Sep 19 '17 at 21:18

The order of properties is not guaranteed. See, for example here:

https://stackoverflow.com/a/5525820/1250301

If you want something ordered, then you need to use an array. The transformation is pretty straightforward:

var aparts = {
    apart1 : {id: "1", status: 2, cost: 10033450},
    apart2 : {id: "2", status: 2, cost: 5214000},
    apart3 : {id: "3", status: 2, cost: 7314300},
    apart4 : {id: "4", status: 1, cost: 9261700}    
};

var arr = Object.keys(aparts).map(function(k) { return aparts[k]; }).sort(function(a,b) { return a.cost - b.cost });

console.log(arr);

score 1 · Answer 2 · answered Sep 19 '17 at 21:40

const aparts = {
    apart1: {id:"1", status: 2, cost: 10033450},
    apart2: {id:"2", status: 2, cost: 5214000},
    apart3: {id:"3", status: 2, cost: 7314300},
    apart4: {id:"4", status: 1, cost: 9261700}    
};

const arr = 
  Object.keys(aparts)
  .map(k => (aparts[k]))
  .sort((a,b) => (a.cost - b.cost))
  .map(k => ({["apart" + k.id]: k}))
;

console.log(arr);

Rick · Answer 3 · 2017-09-19T22:12:29.060

0

I believe you are looking for a Map. Which is what your irregular object matches.

let aparts= {
    apart1: { id: "1", status: 2, cost: 10033450 },
    apart2: { id: "2", status: 2, cost: 5214000 },
    apart3: { id: "3", status: 2, cost: 7314300 },
    apart4: { id: "4", status: 1, cost: 9261700 }
};
let sorted = Object.entries(aparts).map(x => Object.assign(x[1], {
  apart: x[0]
})).sort((a, b) => a.cost - b.cost);

let result = new Map(sorted.map(x => ([x.apart, (delete x.apart, x)])));

console.log(...result)

edited Sep 19 '17 at 22:12

answered Sep 19 '17 at 21:57

Rick

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@dsb I'd like to leave you with a thought... but I'm not sure you have anywhere to put it. – Rick Sep 20 '17 at 22:56
don't understand you – krolovolk Sep 21 '17 at 06:25

Sort Javascript array of objects in place by property value with save keys

3 Answers3