Convert JSON Array to a JSON Object using Javascript

Question

I would like to know how to convert the input json array to a json object in the expected format using Javascript

Here is my input array

[
    {
    "Id": 1,
    "Name": "One"
    },
    {
    "Id": 2,
    "Name": "Two"
    },
    {
    "Id": 3,
    "Name": "Three"
    }
]

Expected json object output

{ "1" : "One",
  "2" :"Two",
  "3" :"Three"
}

What you seem to actually be wanting to know is how to convert an array of objects into a single object that uses the `id` as the property names/keys. — Herohtar, May 09 '19 at 03:18
Possible duplicate of [How do I convert array of Objects into one Object in JavaScript?](https://stackoverflow.com/questions/19874555/how-do-i-convert-array-of-objects-into-one-object-in-javascript) — Herohtar, May 09 '19 at 03:18
Have you tried anything? In that case, please include it. Also, when you say `JSON`, you are implicitly saying that your input and expected output will be strings. Maybe you just want to know how to convert array of objects to a single object. — Shidersz, May 09 '19 at 03:21
Please note that your `Id` entries are numbers in the first structure and become strings in your expected result... — arvymetal, May 09 '19 at 03:24

score 2 · Accepted Answer · answered May 09 '19 at 03:18

2

You can use array reduce and pass an empty object in the accumulator. Then inside the reduce callback update the accumulator array by adding key and value

let obj = [{
  "Id": 1,
  "Name": "One"
}, {
  "Id": 2,
  "Name": "Two"
}, {
  "Id": 3,
  "Name": "Three"
}]


let newObj = obj.reduce(function(acc, curr) {

  acc[curr.Id] = curr.Name;
  return acc;
}, {})


console.log(newObj)

answered May 09 '19 at 03:18

brk

48,835
10
56
78

Agreed. Short version: `obj.reduce((r, v) => ({...r, [v.Id]: v.Name}), {}))` – arvymetal May 09 '19 at 03:21
Just for fun... `obj.reduce((r,{Id, Name}) => ({...r, [Id]: Name}), {})` – rafaelbiten May 09 '19 at 03:27

mingchau · Answer 2 · 2019-05-13T02:20:55.727

1

let arr = [{
    "Id": 1,
    "Name": "One"
  },
  {
    "Id": 2,
    "Name": "Two"
  },
  {
    "Id": 3,
    "Name": "Three"
  }
]

let json1 = {}

for (const s of arr) {
  json1[s.Id] = s.Name
}

console.log(json1)

edited May 13 '19 at 02:20

answered May 09 '19 at 03:20

mingchau

450
3
12

score 0 · Answer 3 · answered May 09 '19 at 03:23

You only need a simple for loop to iterate trough the array and then assign new properties to the resulting object, like so:

let array = [{ "Id": 1, "Name": "One"}, {"Id": 2, "Name": "Two"}, {"Id": 3, "Name": "Three"}];

let obj = {};

for (let i = 0; i < array.length; i++) {
    const elem = array[i];
    obj[elem.Id] = elem.Name;
}

console.log(obj);

score 0 · Answer 4 · answered May 09 '19 at 03:25

Iterate over the array of objects, use Object.values() to get the values for each object and then create new obects using the first value as the key.

var arr = [ { "Id": 1, "Name": "One" }, { "Id": 2, "Name": "Two" }, { "Id": 3, "Name": "Three" } ];

var jsonObj = {};


arr.forEach(function(item){
  var values = Object.values(item);
  jsonObj[values[0]] = values[1];

})

 console.log(jsonObj); // gives {"1": "One","2": "Two","3": "Three"}

Convert JSON Array to a JSON Object using Javascript

4 Answers4