How to rename JSON key

Question

I have a JSON object with the following content:

[
  {
    \"_id\":\"5078c3a803ff4197dc81fbfb\",
    \"email\":\"user1@gmail.com\",
    \"image\":\"some_imag         


        

Answer 1

JSON.parse has two parameters. The second parameter, reviver, is a transform function that can be formatted output format we want. See ECMA specification here.

In reviver function:

• if we return undefined, the original property will be deleted.
• this is the object containing the property being processed as this function, and the property name as a string, the property value as arguments of this function.

const json = '[{"_id":"5078c3a803ff4197dc81fbfb","email":"user1@gmail.com","image":"some_image_url","name":"Name 1"},{"_id":"5078c3a803ff4197dc81fbfc","email":"user2@gmail.com","image":"some_image_url","name":"Name 2"}]';

const obj = JSON.parse(json, function(k, v) {
    if (k === "_id") {
        this.id = v;
        return; # if return  undefined, orignal property will be removed
    }
    return v;
});

const res = JSON.stringify(obj);
console.log(res)

output:

[{"email":"user1@gmail.com","image":"some_image_url","name":"Name 1","id":"5078c3a803ff4197dc81fbfb"},{"email":"user2@gmail.com","image":"some_image_url","name":"Name 2","id":"5078c3a803ff4197dc81fbfc"}]

Answer 2

If anyone needs to do this dynamically:

const keys = Object.keys(jsonObject);

keys.forEach((key) => {

      // CREATE A NEW KEY HERE
      var newKey = key.replace(' ', '_');

      jsonObject[newKey] = jsonObject[key];
      delete jsonObject[key];
   });

jsonObject will now have the new keys.

IMPORTANT:

If your key is not changed by the replace function, it will just take it out of the array. You may want to put some if statements in there.

Answer 3

If your object looks like this:

obj = {
    "_id":"5078c3a803ff4197dc81fbfb",
    "email":"user1@gmail.com",
    "image":"some_image_url",
    "name":"Name 1"
   }

Probably the simplest method in JavaScript is:

obj.id = obj._id
del object['_id']

As a result, you will get:

obj = {
    "id":"5078c3a803ff4197dc81fbfb",
    "email":"user1@gmail.com",
    "image":"some_image_url",
    "name":"Name 1"
   }

Answer 4

If you want to do it dynamically, for example, you have an array which you want to apply as a key to JSON object:

your Array will be like :

var keys = ["id", "name","Address","Phone"] // The array size should be same as JSON Object keys size

Now you have a JSON Array like:

var jArray = [
  {
    "_id": 1,
    "_name": "Asna",
    "Address": "NY",
    "Phone": 123
  },
  {
    "_id": 2,
    "_name": "Euphoria",
    "Address": "Monaco",
    "Phone": 124
  },
  {
    "_id": 3,
    "_name": "Ahmed",
    "Address": "Mumbai",
    "Phone": 125
  }
]

$.each(jArray ,function(pos,obj){
    var counter = 0;
    $.each(obj,function(key,value){
        jArray [pos][keys[counter]] = value;
        delete jArray [pos][key];
        counter++;
    })  
})

Your resultant JSON Array will be like :

[
  {
    "id": 1,
    "name": "Asna",
    "Address": "NY",
    "Phone": 123
  },
  {
    "id": 2,
    "name": "Euphoria",
    "Address": "Monaco",
    "Phone": 124
  },
  {
    "id": 3,
    "name": "Ahmed",
    "Address": "Mumbai",
    "Phone": 125
  }
]

Answer 5

By using map function you can do that. Please refer below code.

var userDetails = [{
  "_id":"5078c3a803ff4197dc81fbfb",
  "email":"user1@gmail.com",
  "image":"some_image_url",
  "name":"Name 1"
},{
  "_id":"5078c3a803ff4197dc81fbfc",
  "email":"user2@gmail.com",
  "image":"some_image_url",
  "name":"Name 2"
}];

var formattedUserDetails = userDetails.map(({ _id:id, email, image, name }) => ({
  id,
  email,
  image,
  name
}));
console.log(formattedUserDetails);

Answer 6

As mentioned by evanmcdonnal, the easiest solution is to process this as string instead of JSON,

var json = [{"_id":"5078c3a803ff4197dc81fbfb","email":"user1@gmail.com","image":"some_image_url","name":"Name 1"},{"_id":"5078c3a803ff4197dc81fbfc","email":"user2@gmail.com","image":"some_image_url","name":"Name 2"}];
    
json = JSON.parse(JSON.stringify(json).split('"_id":').join('"id":'));

document.write(JSON.stringify(json));

This will convert given JSON data to string and replace "_id" to "id" then converting it back to the required JSON format. But I used split and join instead of replace, because replace will replace only the first occurrence of the string.