Sorting a numeric array along with an array of objects in JavaScript

Question

Suppose I generate two arrays One that holds Array of numbers:

[5.65, 3.25, 4.34, 6.78]

And another array that holds objects with some information in them

[car.object1, car.object2, car.object3, car.object4]

And the objects in second array are related to the numbers in first array. So object1 is related to 5.65, object2 to 3.25 and so on.

So I want to sort the array 1 in an ascending order and at the same time sort the array 2 also.

So the result should be:

[3.25, 4.34, 5.65, 6.78]

&

[car.object2, car.object3, car.object1, car.object4]

My Approach: (You can just ignore the below answer as I think it is wrong. It does not work.)

var all = [];
var A = [5.65, 3.25, 4.34, 6.78];
var B = ['store.object1', 'store.object2', 'store.object3', 'store.object4'];

for (var i = 0; i < B.length; i++) {
  all.push({
    'A': A[i],
    'B': B[i]
  });
}

all.sort(function(a, b) {
  return a.A - b.A;
});

A = [];
B = [];

for (var i = 0; i < all.length; i++) {
  A.push(all[i].A);
  B.push(all[i].B);
}

console.log(A, B);

you may consider to use arrays with [] instead of obejcts with {}. — Nina Scholz
– Nina Scholz, Commented Mar 18, 2017 at 17:40
Are you sure those are arrays not objects? They are not valid arrays nor valid objects by the way! — ibrahim mahrir
– ibrahim mahrir, Commented Mar 18, 2017 at 17:41
Similar to stackoverflow.com/questions/6312236/… , stackoverflow.com/questions/11499268/… , stackoverflow.com/questions/13960105/… — le_m
– le_m, Commented Mar 18, 2017 at 18:47

Nina Scholz · Accepted Answer · 2017-03-18 17:48:14Z

2

You could use a temporary array with the indices and sort it with the values of the first array. Then map the sorted array with the values of array1 and array2.

I use strings for the second array, instead of missing objects.

var array1 = [5.65, 3.25, 4.34, 6.78],
    array2 = ['car.object1', 'car.object2', 'car.object3', 'car.object4'],
    temp = array1.map(function (_, i) { return i; });

temp.sort(function (a, b) { return array1[a] - array1[b]; });

array1 = temp.map(function (a) { return array1[a]; });
array2 = temp.map(function (a) { return array2[a]; });

console.log(temp);
console.log(array1);
console.log(array2);

.as-console-wrapper { max-height: 100% !important; top: 0; }

answered Mar 18, 2017 at 17:48

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Kiran Dash Over a year ago

Thanks a lot. It works. And after looking at your syntax, corrected mine. And that works too,

2 revs, 2 users 86% · Accepted Answer · 2017-03-19 13:34:00Z

1

Unless you want to implement the sort yourself, one simple way is to combine the entries from the number array with the entries from the object array (at least briefly), sort that, and then (if necessary) extract the result:

// Setup
var car = {
  object1: {name: "object1"},
  object2: {name: "object2"},
  object3: {name: "object3"},
  object4: {name: "object4"}
};
var nums = [5.65, 3.25, 4.34, 6.78];
var objs = [car.object1, car.object2, car.object3, car.object4];

// Combine
var joined = [];
nums.forEach(function(num, index) {
  joined[index] = {num: num, object: objs[index]};
});

// Sort
joined.sort(function(a, b) {
  return a.num - b.num;
});

// Extract
nums = [];
objs = [];
joined.forEach(function(entry, index) {
  nums[index] = entry.num;
  objs[index] = entry.object;
});

console.log(nums);
console.log(objs);

.as-console-wrapper {
  max-height: 100% !important;
}

But rather than combine, sort, and extract, I'd probably just maintain a single array and add each number to its relevant object, so they always travel together.

edited Mar 19, 2017 at 13:34

community wiki

2 revs, 2 users 86%
T.J. Crowder

6 Comments

T.J. Crowder Over a year ago

I just realized this is basically the solution in the question. I'm afraid I took the "You can just ignore the below answer as I think it is wrong. It does not work." to heart and skipped right over it. Later I saw the comments between you and ibrahim and looked it it.

kind user Over a year ago

What does it exactly mean?

T.J. Crowder Over a year ago

@Kinduser: I don't understand the question.

Kiran Dash Over a year ago

Yes. May be the answer is correct. I am still checking with my code here what I did wrong.

Kiran Dash Over a year ago

I am now trying to understand how everything works. And also thanks for the idea of having both the data together in one array. I tried that in the beginning. But just because I didn't figure out how to separate them later. I choose to keep them separate. DEADLINE pressure. Anyways thanks.

|

trincot · Accepted Answer · 2017-03-18 19:58:03Z

1

Here is an ES6 way to do it:

let a = [5.65, 3.25, 4.34, 6.78];
let b = [{ x:1 }, { x:2 }, { x:3 }, { x: 4}];

[a, b] = a.map( (n, i) => [n, b[i]] ) // zip the two arrays together
          .sort( ([n], [m]) => n-m ) // sort the zipped array by number
          .reduce ( ([a,b], [n, o]) => [[...a, n], [...b, o]], [[],[]] ); // unzip 

console.log(JSON.stringify(a));
console.log(JSON.stringify(b));

edited Mar 18, 2017 at 19:58

answered Mar 18, 2017 at 17:54

trincot

357k38 gold badges282 silver badges338 bronze badges

Comments

kind user · Accepted Answer · 2017-03-18 18:37:47Z

0

I've helped myself with an object containing car.object as the key and it's number as the value. Seems easy&quick solution.

var obj = [{'car.object1': 5.65}, {'car.object2': 3.25}, {'car.object3': 4.34}, {'car.object4': 6.78}],
    objs = obj.sort((a,b) => a[Object.keys(a)] - b[Object.keys(b)]);
    
    console.log(objs.map(v => Object.keys(v)[0]));
    console.log(objs.map(v => v[Object.keys(v)]));
    console.log(objs);

.as-console-wrapper {
  max-height: 100% !important;
}

edited Mar 18, 2017 at 18:37

answered Mar 18, 2017 at 17:58

kind user

42k8 gold badges69 silver badges78 bronze badges

2 Comments

kind user Over a year ago

Yeah, just DV me without a word

kind user Over a year ago

@T.J.Crowder Actually the starting point is the same in every answer. In one of them the next step is map, or forEach or sort. My next step was to drop these arrays into an object. I don't really see anything wrong in it (:

Collectives™ on Stack Overflow

Sorting a numeric array along with an array of objects in JavaScript

4 Answers 4

1 Comment

6 Comments

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

6 Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related