JSON.Stringfy method's replacer argument not working on nested object

Question

I have an object, I want to send this object's simplified version to the server.

{
 "fullName": "Don Corleone",
 "actor": {
  "actorId": 2,
  "name": "Marlon",
  "surname": "Brando",
  "description": "Marlon Brando is widely considered the greatest movie actor of all time... ",
  "heroList": [],
  "photo": "C:\\projects\\files\\actor\\1532955376934.png"
 },
 "heroProfilePhoto": "data:image/png;base64,/9j/...
 "production": {
  "title": "The Godfather",
  "imdbRate": 9.2,
  "genre": "8",
  "releaseDate": "1972-03-23T21:00:00.000Z",
  "director": "Francis Ford Coppola",
  "writer": "Mari Puzo",
  "detail": "The aging patriarch of an organized crime dynasty transfers control of his clandestine empire to his reluctant son."
 }
}"

I have two question::

1) Is it possible to extract something like this with replacer parameter of JSON.stringify() ?

 {
  "fullName": "Don Corleone",
  "actor": {
   "actorId": 2
   }
}"

2) At least can I extract something like this with replacer parameter of JSON.stringify()?

{
 "fullName": "Don Corleone",
 "actor": {
  "actorId": 2,
  "name": "Marlon",
  "surname": "Brando",
  "description": "Marlon Brando is widely considered the greatest movie actor of all time... ",
  "heroList": [],
  "photo": "C:\\projects\\files\\actor\\1532955376934.png"
 },
}"

When I am using like this it's okay:

JSON.stringify(hero, ['fullName']) Result -> "{"fullName":"Don Corleone"}"

But this :

JSON.stringify(hero, ['fullName', 'actor']) Result -> "{"fullName":"Don Corleone","actor":{}}"

Why actor property is empty?

Answer 1

JSON.stringify requires you pass in all of the data you would like returned. 'actor' on its own is not enough.

You want:

JSON.stringify(hero, ['fullName', 'actor', 'actorId'])

EDIT

So I've done some testing, I was curious what would happen if actorId also existed in the parent object, and the results are in.

Both actorId fields are returned by JSON.stringify() in the case where actorId exists inside of the actor object, and inside the parent object. If you would like this not to be the case, you will have to create a more complex function for your needs and pass it to JSON.stringify() as documented here

Here's some examples:

var json = {
    key1: "Value for key1 in parent",
    key2: {
        key3: "Value for key3 in child",
        key4: "Value for key4 in child"
    },
    key4: "Value for key4 in parent"
}

var out1 = JSON.stringify(json, ['key1', 'key3'])
/*
out1 = {
    key1: "Value for key1 in parent"
} // No key3!
*/


var out2 = JSON.stringify(json, ['key1', 'key2', 'key3'])
/*
out2 = {
    key1: "Value for key1 in parent",
    key2: {
        key3: "Value for key3 in child"
    }
}
*/

var out3 = JSON.stringify(json, ['key1', 'key2', 'key3', 'key4'])
/*
out3 = {
    key1: "Value for key1 in parent",
    key2: {
        key3: "Value for key3 in child",
        key4: "Value for key4 in child" // Both key4 returned
    },
    key4: "Value for key4 in parent" // Both key4 returned
}
*/