How to use JSON.stringify() and JSON.parse() in JavaScript

How to use JSON.stringify() and JSON.parse() in JavaScript

JSON.stringify() and JSON.parse() are useful tools for handling JSON-formatted content

There are two useful methods to deal with JSON-formatted content: JSON.stringify() & JSON.parse(), which are useful to learn as a pair.

JSON.parse() takes a JSON string and then transforms it into a JavaScript object.

const myObject = {
  dog: "🐕",
  cat: "🐈",
  koala: "🐨",
  count: 3
};

console.log(JSON.stringify(myObject));
// result: {"dog":"🐕","cat":"🐈","koala":"🐨","count":3}

console.log(JSON.parse(JSON.stringify(myObject)));
// result: Object {dog: "🐕", cat: "🐈", koala: "🐨", count: 3}

JSON.stringify() can take arguments, a replacer function and a string or number to use as a “space” in the returned string.

That means the replacer argument can be used to filter out values if you return undefined, as shown in the following example:

const user = {
  id: 101010,
  name: "Derek",
  email: "[email protected]"
};

function replacer(key, value) {
  if (typeof value === "number") {
    return undefined;
  }
  if (key === "email") {
    return "Removed for privacy";
  }
  return value;
}

console.log(JSON.stringify(user));
// result: {"id":101010,"name":"Derek","email":"[email protected]"}

console.log(JSON.stringify(user, replacer));
// {"name":"Derek","email":"Removed for privacy"}

console.log(JSON.stringify(user, null, "^_^ "));
// result: {
// ^_^ "id": 101010,
// ^_^ "name": "Derek",
// ^_^ "email": "[email protected]"
// }

console.log(JSON.parse(JSON.stringify(user)));
// result: Object {id: 101010, name: "Derek", email: "[email protected]"}

How do you spell stringify backwards? JSON.parse() (Photo by clement fusil on Unsplash)

Angular 9 Tutorial: Learn to Build a CRUD Angular App Quickly

What's new in Bootstrap 5 and when Bootstrap 5 release date?

Brave, Chrome, Firefox, Opera or Edge: Which is Better and Faster?

How to Build Progressive Web Apps (PWA) using Angular 9

What is new features in Javascript ES2020 ECMAScript 2020

Hire Dedicated eCommerce Web Developers | Top eCommerce Web Designers

Build your eCommerce project by hiring our expert eCommerce Website developers. Our Dedicated Web Designers develop powerful & robust website in a short span of time.

JSON Tutorial For Beginners | What is JSON | Learning JSON with JavaScript

JSON Tutorial For Beginners | What is JSON | Learning JSON with JavaScript

Mobile App Development Company India | Ecommerce Web Development Company India

Best Mobile App Development Company India, WebClues Global is one of the leading web and mobile app development company. Our team offers complete IT solutions including Cross-Platform App Development, CMS & E-Commerce, and UI/UX Design.