How to find out which place in an object a given property is in Javascript

Question

For example, if I have an object like:

{"angeredoutsidecontrol":"1","difficultiespileup":"2"}

And then later in a for loop I can access the key of angeredoutsidecontrol , how can I get the value returned as 0, which would represent which place in the object this key is?

Don't depend on the order of keys in an object. What are you actually trying to do? — Gavin, Jul 17 '17 at 20:26
I doubt keys have any guaranteed ordering in the spec, but you can do `Object.keys(yourObject).indexOf("angeredoutsidecontrol")`. I'd recommend rethinking what you're doing though. — Asad Saeeduddin, Jul 17 '17 at 20:26
Iterating over an object is decidedly random. There's no ordering. The best you can do is to dump them into an array and grab that index. — zfrisch, Jul 17 '17 at 20:27
Thanks, I thought I remembered people saying that the order of keys can't be guaranteed, now it's confirmed. — Anthony, Jul 17 '17 at 20:28
@AnthonyMayfield What are you actually trying to do? Maybe we can help sort that issue out. — Gavin, Jul 17 '17 at 20:28
@Gavin, it's fine, I'm just going to go about things a different way, thanks though. — Anthony, Jul 17 '17 at 20:31

score 2 · Accepted Answer · answered Jul 17 '17 at 20:27

There is no guaranteed order for keys of an object.

Definition of object from an old - but still effective in this case - documentation:

4.3.3 Object

An object is a member of the type Object. It is an unordered collection of properties each of which contains a primitive value, object, or function. A function stored in a property of an object is called a method.

If order really matters to you, use array instead. For example:

[{ "angeredoutsidecontrol": "1" }
 { "difficultiespileup": "2" }];

score 0 · Answer 2 · answered Jul 17 '17 at 20:28

0

The order of JSON objects is not maintained, so you can't do this.

[Is the order of elements in a JSON list maintained?

answered Jul 17 '17 at 20:28

Paul Cuddihy

362
4
12

These two terms are used interchangeably in this context. – Paul Cuddihy Jul 19 '17 at 13:31

score 0 · Answer 3 · answered Jul 17 '17 at 20:31

0

var myMoods = ["angeredoutsidecontrol","difficultiespileup"];

and

myMoods.indexOf( 'angeredoutsidecontrol' )

gives you position in your list

answered Jul 17 '17 at 20:31

Jarek Kulikowski

1,389
6
9

How to find out which place in an object a given property is in Javascript

3 Answers3