How to append a property to a Json object inside a Json Array? [duplicate]

Question

I have the following variable holding a json array.

let requestJson = '{ "data": [ { "type": "Type1", "value": "MyValue" } ] }';

I would like to add a property called "Id" to the above object inside data array. I expect to get something like;

{ "data": [ { "type": "Type1", "value": "MyValue", "id": "123" } ] }

How can I achieve this? I tried the following:

requestJson["data"][0]["id"] = '123';

But when I print requestJson["data"] I'm getting undefined. Would appreciate any help in appending the "Id" attribute to the object inside the array above. Thanks in advance.

requestJson is a string, not an object. Use JSON.parse(requestJson) first (or eliminate the outer single quote marks). Also, you can do requestObj.data[0].id = '123' — Andrew Parks
– Andrew Parks, Commented Jan 11, 2023 at 22:01
@pilchard did refer to that question but I was confused since I had to append to the object inside the array, instead of updating the array with a new object. Thanks — AnOldSoul
– AnOldSoul, Commented Jan 11, 2023 at 22:08
@AnOldSoul your access attempt was correct, it was just the parsing that you were missing — pilchard
– pilchard, Commented Jan 11, 2023 at 22:30

JuanDM · Accepted Answer · 2023-01-11 22:04:29Z

3

You need to parse your string to convert it to an Object and after that you can manipulate the data attribute

let requestJson = '{ "data": [ { "type": "Type1", "value": "MyValue" } ] }';
const parsedObject = JSON.parse(requestJson)
parsedObject.data[0].id = 1
console.log(parsedObject)

answered Jan 11, 2023 at 22:04

JuanDM

1,33011 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to append a property to a Json object inside a Json Array? [duplicate]

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related