how to sort javascript objects?

Question

Here are my objects:

var user1 = new Object();
user1.username = "user1"; user1.sex="m"; user1.age=20;

var user2 = new Object();
user2.username = "user1"; user2.sex="f";user2.age=30;

var user3 = new Object();
user3.username = "user3"; user3.sex="f";user3.age=22;

var users = {"john":user1, "jerry": user2, "marry":user3};

How can I sort users by age ?

use any sort algorithm available... note however, object is not ordered. — taesu, Sep 02 '15 at 19:43
Don't know your implementation but `users` should be an `array` not `object`. And then search for an algo to sort array of objects. — Jehanzeb.Malik, Sep 02 '15 at 19:44
a) There is no JSON here, this is not JSON. JSON is a *string representation* of data (that so happens to be based off of JavaScript syntax). b) JavaScript objects are **unordered**. If you need a specific order, use an array. — gen_Eric, Sep 02 '15 at 19:46
P.S. Use `user1 = {};` instead of `var user1 = new Object();`. P.P.S. You can also just do `var user1 = {username: 'user1', sex: 'm', age: 20};`. — gen_Eric, Sep 02 '15 at 19:47

score 2 · Answer 1 · edited Sep 02 '15 at 20:03

2

First, consider storing users in an array, not an object

var users = [user1, user2, user3];

then you need a sort function

//a and be will be passed in, you need to tell it which one is greater
function sortByAge(a,b) {

  if (a.age > b.age) return 1;
  if (a.age < b.age) return -1;
  /* else */ return 0;

  //how I had it previously that people commented on
  //return a.age > b.age;  
}

then you can use that sort wherever you need

users.sort(sortByAge);

edited Sep 02 '15 at 20:03

gen_Eric

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answered Sep 02 '15 at 19:45

Charlie Wynn

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[That comparison function is not enough](http://stackoverflow.com/q/24080785/1048572) – Bergi Sep 02 '15 at 19:48
@Bergi why not?.. worked for me – Charlie Wynn Sep 02 '15 at 19:53
Please closely read the explanation in the linked Q&A. Try out the counterexample generator… – Bergi Sep 02 '15 at 19:54
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@CharlieWynn answer to your exact question is in the accepted answer on the link :P – Jehanzeb.Malik Sep 02 '15 at 19:55
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@Jehanzeb.Malik ¯\_(ツ)_/¯ did not even realize that was a link somehow :P – Charlie Wynn Sep 02 '15 at 19:56
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@Bergi I can't even explain how long I've been doing it like that - thanks for the link! – Charlie Wynn Sep 02 '15 at 19:59
@CharlieWynn: Thanks for the edit :-) – Bergi Sep 02 '15 at 20:02
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@CharlieWynn: Since the `age` is an int, you can actually `return a.age - b.age;` inside `sortByAge()`. The comparison function just needs to return any positive number, any negative number, or zero. – gen_Eric Sep 02 '15 at 20:02
too clever for me @RocketHazmat - thanks for editing in the .age btw – Charlie Wynn Sep 02 '15 at 20:05
Problem is I fetch users by id ex: users["1"].age etc.. so I cannot have an array but associative array – yarek Sep 03 '15 at 08:46

how to sort javascript objects?

1 Answers1