Add field to JSON

Question

I want to add a field to JSON. I do have a working solution, but it's ugly (using eval). Is there a nicer way to add a field?

var json = {};
var id = "test";
eval("json." + id + " = 5;");
console.log(json.test);

UPDATE: Sorry, my question was somewhat unclear. I want to use the variable id, which has the value of the new field.

Cheers, Bernhard

`json[id] = 5`. Also, that's a JavaScript object, not JSON, don't get them mixed up! http://stackoverflow.com/questions/2904131/what-is-the-difference-between-json-and-object-literal-notation — Joe Clay, Jun 09 '16 at 09:00
That's not JSON, that's a javascript object. You seem to want to add a property with a certain value. No offense, but searching online should easily yield useful results. Are we missing some info? — Jeroen, Jun 09 '16 at 09:00
please have a look here: http://stackoverflow.com/questions/4968406/javascript-property-access-dot-notation-vs-brackets — Nina Scholz, Jun 09 '16 at 09:02

Krishnakant · Accepted Answer · 2016-06-10T05:10:13.160

4

You can use like below instead:

Use like this:

json[id] = 5;

Thus, in your case:

var json = {};
var id = "test";
json[id] = 5;
console.log(json.test); //will print 5
// OR
console.log(json['test']); //will print 5

edited Jun 10 '16 at 05:10

answered Jun 09 '16 at 09:01

Krishnakant

score 2 · Answer 2 · answered Jun 09 '16 at 09:00

2

you can add like this :

var json = {};
json.test = 5;
console.log(json.test);

or

var json = {};
json["test"] = 5;
console.log(json.test);

Hope it helps :)

answered Jun 09 '16 at 09:00

Arun AK

Razvan Dumitru · Answer 3 · 2016-06-09T09:01:27.767

0

You can use

var json = {};
var id = "test";
eval("json." + id + " = 5;");
console.log(json.test);

and this

var json2 = {};
json2.test = 5;
console.log(json2.test);

or this

var json3 = {};
json3["test"] = 5;
console.log(json3.test);

First example is undesirable.

edited Jun 09 '16 at 09:01

answered Jun 09 '16 at 09:00

Razvan Dumitru

3 Answers3