In JavaScript, private variables are not included in the JSON.stringify output

Question

In JavaScript, private variables are not included in the JSON.stringify output

Imagine creating a class called Rectangle with private fields like width and height, initializing them in the constructor. However, when calling JSON.stringify on an instance of this class, it returns an empty object without including the private members.

Is there a simpler way to make private fields visible in the JSON output without having to create a toJSON method for each member? It seems tedious to manually include every private field in the toJSON method.

javascript json class private class-fields

Answer 1

Answer №1

Restricted properties can only be accessed within the class itself. To access them, you must create a custom serialization method:

class Square {
  #side;
  constructor() {
    this.#side = 4;
  }

  serialize() {
    return JSON.stringify({['#side']: this.#side})
  }

}

let sq = new Square();

console.log(sq.serialize())

Answer 2

Restricted properties can only be accessed within the class itself. To access them, you must create a custom serialization method:

class Square {
  #side;
  constructor() {
    this.#side = 4;
  }

  serialize() {
    return JSON.stringify({['#side']: this.#side})
  }

}

let sq = new Square();

console.log(sq.serialize())

Answer 3

Answer №2

To simplify the process of specifying all the members individually, one approach is to utilize a solitary private data property within the instance and then handle serialization and deserialization through that property:

class Square {
   #data;
   constructor(data) {
      this.#data = data;
   }
   getSideLength = () => this.#data.sideLength;
   toJson = () => JSON.stringify(this.#data);
}
const s = new Square({ sideLength: 5 });
console.log(s.getSideLength());
const serialized = s.toJson();
console.log(serialized);

const reconstructed = new Square(JSON.parse(serialized));
console.log(reconstructed.getSideLength());

Answer 4

To simplify the process of specifying all the members individually, one approach is to utilize a solitary private data property within the instance and then handle serialization and deserialization through that property:

class Square {
   #data;
   constructor(data) {
      this.#data = data;
   }
   getSideLength = () => this.#data.sideLength;
   toJson = () => JSON.stringify(this.#data);
}
const s = new Square({ sideLength: 5 });
console.log(s.getSideLength());
const serialized = s.toJson();
console.log(serialized);

const reconstructed = new Square(JSON.parse(serialized));
console.log(reconstructed.getSideLength());

Answer 5

Answer №3

Avoid utilizing private variables as they serve no purpose.

Answer 6

Avoid utilizing private variables as they serve no purpose.

In JavaScript, private variables are not included in the JSON.stringify output

Answer №1

Answer №2

Answer №3

Similar questions

Creating dynamic height based on width using JavaScript

Warning: Unidentified JavaScript alert(notification) encountered without declaring a

Embedding images using a blob or base64 format does not function properly on iOS devices

Creating the necessary JSON structure in iOS: A step-by-step guide

Capture and transform every alert into a notification

Setting a custom tab as the default route in Expo Router without relying on an index.tsx file - here's how!

Alter the classification of the tag

Having trouble getting my Node.js Express code to display 'Hello World' on Cloud 9 platform

What is the best way to change the background color for my photo gallery?

Changing the shape of a background using CSS when hovering

Chrome has some issues with resizing the SVG Pattern element

Utilizing AJAX in ASP.net Web API 2 to send and receive JSON data efficiently

Disabling pointer-events on material-ui textField input is ineffective

Is there a way to automatically redirect my page after clicking the submit button?

Here is a unique version: "In Javascript, users can trigger the function this.Something() from within this.img.onload by

I am encountering an issue where I am unable to send a HashMap String to a PHP server, and I am not receiving a JSONArray in the

Ensuring Data Integrity in Angular JS Forms

Having trouble with Angular ngRoute functionality?

Decode a JSON entity featuring a distinct layout and identical identifier

Certain CSS styles for components are missing from the current build