how to update specific value in json array

Question

New to manipulating JSON, I appreciate the help! This project uses VueJs 2 if that makes a difference.

I am trying to update a key value, in this example it is "group" for a specific applicant identified by the ID.

I am trying to accomplish something along of lines of:

WHERE applicantID = 3 SET group = 4

This is a sample of the JSON I am dealing with:

{
    "applicantID" : 3,
    "fullName": "name",
    "value1": 30,
    "value1": 31,
    "value1": 40,
    "value1": 41,
    "value1": "50",
    "value1": "51",
    "group": 0,
    "flag": true,
},
{
    "applicantID" : 4,
    "fullName": "name",
    "value1": 30,
    "value1": 31,
    "value1": 40,
    "value1": 41,
    "value1": "50",
    "value1": "51",
    "group": 0,
    "flag": false,
}

Possible duplicate of [How to access JSON encoded data of an array using javascript](https://stackoverflow.com/questions/21040794/how-to-access-json-encoded-data-of-an-array-using-javascript) — Aniket Sahrawat, Jan 12 '18 at 22:34
This looks like it's part of an array. Assuming arr is a defined array, arr[0]["group"] = 4. — Jonathan Chaplin, Jan 12 '18 at 22:35
You have duplicate property names (value1) - that won't work. — James, Jan 12 '18 at 22:44

score 8 · Accepted Answer · answered Jan 12 '18 at 22:34

8

You can do it like this:

var item = array.find(x => x.applicantID == 3);
if (item) {
  item.group = 4;
}

It will change a value of the group in the original array.

answered Jan 12 '18 at 22:34

Sergii Rudenko

2,603
1
22
24

What if there is more than one item that has ID 3? – Abid Hasan Jan 12 '18 at 22:39
Fantastic! That was exactly what I needed. Thank you very much! – JonYork Jan 12 '18 at 22:50
@Sergii what if you have to update multiple records then what would be the approach since this will update only one object in the array – Rizwan Patel Feb 17 '21 at 12:19

score 1 · Answer 2 · answered Oct 28 '19 at 18:34

1

if you have to compare multiple fields you can use this .as an adjustment onto Sergii's answer

var item = array.find(x => {
      return x.applicantID == 3 && x.fullName == "name" ;
     });
   if (item) {
     item.group = 4;
    }

answered Oct 28 '19 at 18:34

Zadiki Hassan Ochola

746
15
25

score 0 · Answer 3 · answered Apr 13 '23 at 16:26

You can update a specific value in a JSON array by first getting the specific index then accessing the object property name to edit the value as illustrated below


let users = [{name:"John", DOB:"1991", gender:"male"}, {name:"mary", DOB:"1993", gender:"female"}];

//change DOB of Mary
users[1].DOB = "1995";

NB You can also loop over the JSON array to update a value at a specific index using the same logic.

how to update specific value in json array

3 Answers3