How to get object values with dynamic variable from json

Question

I want to get the value of an object field from JSON. I have a dynamic variable let check_permission_key = 'ratingscalename'; and have one JSON

let overwrite_key = {
  studentimage: 'student',
  ratingscalename: 'rating-scale-name',
  ratingscale: 'rating-scale-name',
  capturesettingset: 'capture-setting-set',
  capturesetting: 'capture-setting-set',
  eventlog: 'event-log',
  goalcategorie: 'goal-category',
  userimage: 'user',
  datasheetlink: 'datasheet',
  datasheetgoal: 'datasheet',
};

let get_value = overwrite_key.check_permission_key;

So I am fetching the data like this, but it is not working can anyone please help me to resolve this issue?

Mamun · Accepted Answer · 2019-10-08T13:32:10.370

6

To access the object property value using a variable use Bracket ([]) notation:

let overwrite_key = {'studentimage':'student','ratingscalename':'rating-scale-name','ratingscale':'rating-scale-name','capturesettingset':'capture-setting-set','capturesetting':'capture-setting-set','eventlog':'event-log','goalcategorie':'goal-category','userimage':'user','datasheetlink':'datasheet','datasheetgoal':'datasheet'};
let check_permission_key = 'ratingscalename';
let get_value = overwrite_key[check_permission_key];
console.log(get_value);

edited Oct 08 '19 at 13:32

answered Oct 08 '19 at 13:21

Mamun

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thanks it is working now – Nikul Panchal Oct 08 '19 at 13:23
@NikulPanchal, you are most welcome:) – Mamun Oct 08 '19 at 13:24

score 3 · Answer 2 · answered Oct 08 '19 at 13:20

3

Objects in javascript are pretty much arrays with String keys, so you can access a dynamic property like this:

let get_value = overwrite_key[check_permission_key];

answered Oct 08 '19 at 13:20

Ayrton

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ohhh thanks, it is working now – Nikul Panchal Oct 08 '19 at 13:23

score -1 · Answer 3 · answered Oct 08 '19 at 13:24

-1

You can use eval() function.

let overwrite_key = {
  studentimage: 'student',
  ratingscalename: 'rating-scale-name',
  ratingscale: 'rating-scale-name',
  capturesettingset: 'capture-setting-set',
  capturesetting: 'capture-setting-set',
  eventlog: 'event-log',
  goalcategorie: 'goal-category',
  userimage: 'user',
  datasheetlink: 'datasheet',
  datasheetgoal: 'datasheet',
};
let check_permission_key = 'ratingscalename';
let get_value = eval(`overwrite_key.${check_permission_key}`);
console.log(get_value);

JavaScript eval() Function

answered Oct 08 '19 at 13:24

bli07

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5
16

1

You should avoid `eval`. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval#Do_not_ever_use_eval! – Ayrton Oct 08 '19 at 13:32
Yes, you are right. But it can be a solution in some situations. – bli07 Oct 08 '19 at 13:36

How to get object values with dynamic variable from json

3 Answers3