Pushing objects inside JSON array

Question

I need to push a new ID for my data array. If I try pushing into data it creates one more object but not adding into the array for each.

Data:

[{"devices":{"dID":"TLSM01"},"uuid":"e863c776-f939-4761-bbce-bf0501b42ef7"},
 {"devices":{"dID":"TLSM01"},"uuid":"5a0cd70d-891d-48d8-b205-e92e828ac445"}]

Data need to be added:

{"EntityID":"12458412548"}

Final Result:

[{"devices":{"dID":"TLSM01","EntityID":"12458412548"},"uuid":"e863c776-f939-4761-bbce-bf0501b42ef7"},
 {"devices":{"dID":"TLSM01","EntityID":"12458412548"},"uuid":"5a0cd70d-891d-48d8-b205-e92e828ac445"}]

Code:

var data = [{
  "devices": {
    "dID": "TLSM01"
  },
  "uuid": "e863c776-f939-4761-bbce-bf0501b42ef7"
}, {
  "devices": {
    "dID": "TLSM01"
  },
  "uuid": "5a0cd70d-891d-48d8-b205-e92e828ac445"
}]
data.push({
  "EntityID": "test"
});
console.log(data);

JSON is a *textual notation* for data exchange. [(More.)](http://stackoverflow.com/a/2904181/157247) By the time you're pushing a value into that array, it's not JSON. It's just an array. It may never have been JSON. — T.J. Crowder, May 02 '17 at 07:10
*"If I try pushing into data it creates one more object but not adding into the array for each."* Show us your code for that. We can't help you with code we cannot see. — T.J. Crowder, May 02 '17 at 07:11
Can you simplify the example? An endlessly scrolling one-liner is impossible to fully comprehend. — deceze, May 02 '17 at 07:16
If your "final result" is the *desired* result, then `data[0].devices.EntityID = "test"`, because you're trying to add a property to the object that is the first element in the array, not add an element to an array. Or use a loop to add the property to each element. — nnnnnn, May 02 '17 at 07:16
@nnnnnn I have the suspicion he wants to add to *every* element in the array, but I'm not going to try to pick that gobbledygook apart… — deceze, May 02 '17 at 07:19
@deceze - Yeah, I was just editing my comment to suggest a loop. It *is* very difficult to read with all the nesting all on one line like that. — nnnnnn, May 02 '17 at 07:20

Weedoze · Accepted Answer · 2017-05-02T07:28:40.353

1

data is an array containing objects. If you want to add a property to each object you have to iterate over the array.

You need to add a new property to the object devices which is not an array thus you cannot use .push()

var data = [{"devices":{"dID":"TLSM01"},"uuid":"e863c776-f939-4761-bbce-bf0501b42ef7"},{"devices":{"dID":"TLSM01"},"uuid":"5a0cd70d-891d-48d8-b205-e92e828ac445"}];

data.forEach(d=>d.devices['EntityID']="test");

console.log(data);

edited May 02 '17 at 07:28

answered May 02 '17 at 07:19

Weedoze

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Why use the brackets form? (Just curious.) Also note that their "final result" doesn't cap the `E` in `EntityID` although they did in their example. – T.J. Crowder May 02 '17 at 07:22
@T.J.Crowder I do not have any reason to use the brackets form. It was just in case he needs to use different names with symbols. Actually, OP is using an upper case `E` – Weedoze May 02 '17 at 07:24
Thanks -- they edited again! Previously they weren't. :-) – T.J. Crowder May 02 '17 at 07:26

T.J. Crowder · Answer 2 · 2017-05-02T07:26:57.770

If your "final result" is the result you want to achieve, you don't want to push anything. You're just setting a new property on the entries that already exist in the array. So, loop through and do that:

data.forEach(function(entry) {
    entry.EntityID = "12458412548";
});

(Or a simple for loop.)

If you're using ES2015+ syntax, you could use an arrow function:

data.forEach(entry => entry.EntityID = "12458412548");

...or a for-of loop:

for (const entry of data) {
    entry.EntityID = "12458412548";
}

score 0 · Answer 3 · answered May 02 '17 at 08:20

DEMO

var jsonObj = [{"devices":{"dID":"TLSM01"},"uuid":"e863c776-f939-4761-bbce-bf0501b42ef7"},
 {"devices":{"dID":"TLSM01"},"uuid":"5a0cd70d-891d-48d8-b205-e92e828ac445"}];
 
jsonObj.map(item => item.devices["EntityID"] = "12458412548");

console.log(jsonObj);

Pushing objects inside JSON array

3 Answers3

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