What is JSON? — JS Technical Interview Questions & Answers

A lightweight text format for structured data.

What is JSON?

  • JSON (intro) is a JS topic. In plain words you use it for let total = 0 in a cart script. Don’t start with a slogan — start with that picture.
  • Smallest example: let for change, const for fixed. Type it, run it, and say what you see. If you can do that from memory, you know JSON (intro).
  • From the example next to this theory: A lightweight text format for structured data.
  • Trap: var leak / const reassign. Fix that before you talk about advanced JS.
  • Viva: what is JSON (intro)? Then show let for change, const for fixed. Then name the trap.

Technical Interview Tip: What is JSON (intro)? Show this: let for change, const for fixed. Trap: var leak / const reassign.

Code Examples for What is JSON?

What is JSON? — working example

const user = { name: "Ada", skills: ["JS", "SQL"] };
const raw = JSON.stringify(user);
const back = JSON.parse(raw);
console.log(raw);
console.log(back.name, back.skills.length);

// fetch sketch (lab uses parse stand-in):
async function load() {
  const data = JSON.parse('{"ok":true}');
  return data.ok;
}
load().then(console.log);

What is JSON? — jSON is text; stringify/parse convert to plain data. fetch() loads JSON from APIs in the browser/Node.

How to Explain What is JSON? to an Interviewer

What is JSON (intro)?

Used for let total = 0 a cart script Not just the heading

Give one small example of JSON (intro).

let for change, const for fixed A lightweight text format for structured data

What mistake do beginners make with JSON (intro)?

var leak / const reassign Show the fix

Where do you use JSON (intro)?

a cart script let total = 0