Simple function to sort an array of objects

Question

I would like to create a (non-anonymous) function that sorts an array of objects alphabetically by the key name. I only code straight-out JavaScript so frameworks don't help me in the least.

var people = [
    {'name': 'a75', 'item1': false, 'item2': false},
    {'name': 'z32', 'item1': true,  'item2': false},
    {'name': 'e77', 'item1': false, 'item2': false}
];

What do you have so far? Why do you explicitly want a non-anonymous function? — pimvdb, Nov 17 '11 at 22:12
A non-anonymous function sorting(json_object,key_to_sort_by) {} — John, Nov 17 '11 at 22:14
Added the quotes, haven't coded for a few days! Just want to figure out how JSON and JavaScript set the key and then sort. Figure if it's not integer based I could use the sort method perhaps? — John, Nov 17 '11 at 22:16
Anonymous function example: window.onload = function() {/* stuff();*/} — John, Nov 17 '11 at 22:16
What you list above is not JSON, it is a plain JavaScript object. JSON is the string encoded version of a JavaScript object. — Matt, Nov 17 '11 at 22:17
Sorting an object (array-like since JavaScript calls it an object) essentially as far as I see it only tagging it as JSON...not sure if there is any special JSON - specific code. If I call out the names then I want, 'a75','e77','z32' when sorting by name. — John, Nov 17 '11 at 22:19
[duplicate?](http://stackoverflow.com/questions/881510/json-sorting-question) — dani herrera, Nov 17 '11 at 22:19
Okay, I keep seeing a, b and it's not processing in my head. Is that a loop of some sort that I'm not figuring? I'm not sure how to *call* that and that's an anonymous function, I want a normal function I can recall and work on please. — John, Nov 17 '11 at 22:21
@John A sort function takes 2 arguments (such as a,b) because you are comparing 2 different items each time, until sorting is completed. A sort function returns 1 if the 'a' should be after the 'b' argument, -1 if it should be before, or 0 if they are equivalent — Matt, Nov 17 '11 at 22:32
possible duplicate of [How to sort an array of objects?](http://stackoverflow.com/questions/979256/how-to-sort-an-array-of-objects) — Sarfraz, Nov 19 '11 at 10:14
I took the liberty of removing mentions to JSON because it's really not about JSON and it's a good reference question. — JJJ, Dec 29 '12 at 12:31
@EvanCarroll I asked this question in 2011 and the question *you* referenced was asked 11 hours ago. Stop wasting people's time. — John, May 25 '16 at 01:43

score 142 · Accepted Answer · edited Jun 14 '19 at 10:32

142

How about this?

var people = [
{
    name: 'a75',
    item1: false,
    item2: false
},
{
    name: 'z32',
    item1: true,
    item2: false
},
{
    name: 'e77',
    item1: false,
    item2: false
}];

function sort_by_key(array, key)
{
 return array.sort(function(a, b)
 {
  var x = a[key]; var y = b[key];
  return ((x < y) ? -1 : ((x > y) ? 1 : 0));
 });
}

people = sort_by_key(people, 'name');

This allows you to specify the key by which you want to sort the array so that you are not limited to a hard-coded name sort. It will work to sort any array of objects that all share the property which is used as they key. I believe that is what you were looking for?

And here is a jsFiddle: http://jsfiddle.net/6Dgbu/

edited Jun 14 '19 at 10:32

John

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answered Nov 17 '11 at 22:20

David Brainer

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16

Is it possible to sort by 2 keys? eg. 'last_name', 'first_name'? (similar to mysql's ORDER BY field). Thanks! – Josiah Jan 02 '14 at 23:49
@DavidBrainer-Banker - I really like the solution in this answer -- what if I wanted to sort by MULTIPLE keys? Is that possible with this solution or better handled another way? – tamak Dec 02 '15 at 13:51
for Descending order of sorting , what should be done ? – Ananta Prasad Aug 31 '16 at 06:53
1

It doesn't work with upper/lowercase values. Please update the code with `var x = a[key].toLowerCase(); var y = b[key].toLowerCase();` – Ignacio Ara Jan 08 '19 at 11:12
8

This algorithm messes up stacksort. Please fix – Justin AnyhowStep Jul 17 '19 at 21:02
2

Hello from StackSort ! Nice answer, did the job. – Toodoo Oct 04 '19 at 14:27
And to change the sort order, do this: return array.sort(function(b,a) – vr_driver Mar 23 '20 at 11:20

pimvdb · Answer 2 · 2011-11-17T22:23:52.517

32

You can sort an array ([...]) with the .sort function:

var people = [
    {'name': 'a75', 'item1': false, 'item2': false},
    {'name': 'z32', 'item1': true,  'item2': false},
    {'name': 'e77', 'item1': false, 'item2': false},
];

var sorted = people.sort(function IHaveAName(a, b) { // non-anonymous as you ordered...
    return b.name < a.name ?  1 // if b should come earlier, push a to end
         : b.name > a.name ? -1 // if b should come later, push a to begin
         : 0;                   // a and b are equal
});

edited Nov 17 '11 at 22:23

answered Nov 17 '11 at 22:18

pimvdb

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Thanks though that is an annoymous function, I'm trying to do function sort_example(object_name,key_to_sort_by) {} – John Nov 17 '11 at 22:23
1

@John: It's a named function expression now :) What you want is not too difficult, have a try. – pimvdb Nov 17 '11 at 22:24
so after sort what should i console, sorted or people – Freddy Sidauruk Apr 02 '18 at 07:08

score 9 · Answer 3 · answered Nov 17 '11 at 22:18

9

This isn't a JSON question, per se. Its a javascript array question.

Try this:

people.sort(function(a,b){ 
    var x = a.name < b.name? -1:1; 
    return x; 
});

answered Nov 17 '11 at 22:18

Geuis

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I'm trying to do function sort_example(object_name,key_to_sort_by) {} – John Nov 17 '11 at 22:23
2

+1 I used this to sort prices and I just inverted the bracket '<' for '>' and I got the prices sorted from lowest to highest. Thank you! – Dan Palmieri Sep 15 '14 at 20:42
1

This can blow badly because of comparing same elements returning `1`. Depending on the sort function user, anything can happen. – maaartinus May 11 '17 at 14:18

score 5 · Answer 4 · answered Jun 26 '18 at 18:22

5

I modified @Geuis 's answer by using lambda and convert it upper case first:

people.sort((a, b) => a.toLocaleUpperCase() < b.toLocaleUpperCase() ? -1 : 1);

answered Jun 26 '18 at 18:22

Ryan Wibawa

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Nate Getch · Answer 5 · 2017-09-04T22:01:59.847

4

My solution for similar sort problem using ECMA 6

var library = [
        {name: 'Steve', course:'WAP', courseID: 'cs452'}, 
        {name: 'Rakesh', course:'WAA', courseID: 'cs545'},
        {name: 'Asad', course:'SWE', courseID: 'cs542'},
];

const sorted_by_name = library.sort( (a,b) => a.name > b.name );

for(let k in sorted_by_name){
    console.log(sorted_by_name[k]);
}

edited Sep 04 '17 at 22:01

answered Sep 04 '17 at 21:45

Nate Getch

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Interesting though subjective to browser share / compatibility. If it will work in IE11 then 2017 compatibility is fair otherwise if it requires IE12 ("Edge") it will have to wait until circa 2020. Looks slightly less verbal...though when I originally posted this I asked for a non-anonymous function I could call. – John Sep 05 '17 at 01:08
Are you sure this is meant to work according to standards? `<` on strings returns just `true` or `false` on Node v14.17.0, not the desired -1, 0, 1. – Ciro Santilli OurBigBook.com Jun 17 '21 at 10:28

score 2 · Answer 6 · edited Oct 25 '18 at 23:09

Array.prototype.sort_by = function(key_func, reverse=false){
    return this.sort( (a, b) => ( key_func(b) - key_func(a) ) * (reverse ? 1 : -1) ) 
}

Then for example if we have

var arr = [ {id: 0, balls: {red: 8,  blue: 10}},
            {id: 2, balls: {red: 6 , blue: 11}},
            {id: 1, balls: {red: 4 , blue: 15}} ]

arr.sort_by(el => el.id, reverse=true)
/* would result in
[ { id: 2, balls: {red: 6 , blue: 11 }},
  { id: 1, balls: {red: 4 , blue: 15 }},
  { id: 0, balls: {red: 8 , blue: 10 }} ]
*/

or

arr.sort_by(el => el.balls.red + el.balls.blue)
/* would result in
[ { id: 2, balls: {red: 6 , blue: 11 }},    // red + blue= 17
  { id: 0, balls: {red: 8 , blue: 10 }},    // red + blue= 18
  { id: 1, balls: {red: 4 , blue: 15 }} ]   // red + blue= 19
*/

score 1 · Answer 7 · answered Dec 23 '15 at 08:01

1

var data = [ 1, 2, 5, 3, 1]; data.sort(function(a,b) { return a-b });

With a small compartor and using sort, we can do it

answered Dec 23 '15 at 08:01

iknowsomething

11
1

score 0 · Answer 8 · answered Dec 26 '19 at 23:48

This is how simply I sort from previous examples:

if my array is items:

0: {id: 14, auctionID: 76, userID: 1, amount: 39}
1: {id: 1086, auctionID: 76, userID: 1, amount: 55}
2: {id: 1087, auctionID: 76, userID: 1, amount: 55}

I thought simply calling items.sort() would sort it it, but there was two problems: 1. Was sorting them strings 2. Was sorting them first key

This is how I modified the sort function:

for(amount in items){
if(item.hasOwnProperty(amount)){

i.sort((a, b) => a.amount - b.amount);
}
}

score 0 · Answer 9 · answered Apr 12 '23 at 13:45

0

Sorting alphabetically with lambda function:

arr.sort((a, b) => a.name.localeCompare(b.name));

answered Apr 12 '23 at 13:45

Dacili

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score -1 · Answer 10 · answered Sep 08 '17 at 11:58

-1

var library = [
        {name: 'Steve', course:'WAP', courseID: 'cs452'}, 
        {name: 'Rakesh', course:'WAA', courseID: 'cs545'},
        {name: 'Asad', course:'SWE', courseID: 'cs542'},
];

const sorted_by_name = library.sort( (a,b) => a.name > b.name );

for(let k in sorted_by_name){
    console.log(sorted_by_name[k]);
}

answered Sep 08 '17 at 11:58

ashoka pal

1

1

It is always nice to put some explanatory text along with your code, when answering questions. – Leonardo Alves Machado Sep 08 '17 at 12:03
The compare function returns a boolean, it should return a number – marcovtwout Nov 06 '17 at 10:45

score -1 · Answer 11 · answered May 12 '22 at 04:22

-1

var library = [
        {name: 'Steve', course:'WAP', courseID: 'cs452'}, 
        {name: 'Rakesh', course:'WAA', courseID: 'cs545'},
        {name: 'Asad', course:'SWE', courseID: 'cs542'},
];

const sorted_by_name = library.sort( (a,b) => a.name > b.name ? 1:-1 );

for(let k in sorted_by_name){
    console.log(sorted_by_name[k]);
}

answered May 12 '22 at 04:22

Balaji Koneru

1

2

As it’s currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community May 12 '22 at 10:37

score -3 · Answer 12 · answered Nov 17 '11 at 22:22

-3

var people = 
[{"name": 'a75',"item1": "false","item2":"false"}, 
{"name": 'z32',"item1": "true","item2":  "false"}, 
{"name": 'e77',"item1": "false","item2": "false"}]; 

function mycomparator(a,b) {   return parseInt(a.name) - parseInt(b.name);  } 
people.sort(mycomparator);

something along the lines of this maybe (or as we used to say, this should work).

answered Nov 17 '11 at 22:22

Brian

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`parseInt('a75')` is `NaN` so this won't really work I guess. – pimvdb Nov 17 '11 at 22:25
I don;t think this is appropriate solution when we are dealing with string value, because parseInt on string might give unexpected value, but yaa if you are comparing a string having numeric or decimal value then it will work – Dinesh Gopal Chand Aug 11 '19 at 03:23

Simple function to sort an array of objects

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