What are Cookies? — JS Technical Interview Questions & Answers

Small key-value pairs stored by the browser per domain.

What are Cookies?

  • What are Cookies (js 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 What are Cookies (js intro).
  • From the example next to this theory: Small key-value pairs stored by the browser per domain.
  • Trap: var leak / const reassign. Fix that before you talk about advanced JS.
  • Viva: what is What are Cookies (js intro)? Then show let for change, const for fixed. Then name the trap.

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

Code Examples for What are Cookies?

What are Cookies? — working example

// Browser:
// document.cookie = "theme=dark; Max-Age=86400; Path=/; SameSite=Lax";
// localStorage.setItem("theme", "dark");
// sessionStorage.setItem("draft", "hello");

// Runnable stand-in:
const jar = { theme: "dark" };
const store = new Map([["theme", "dark"]]);
console.log(jar.theme, store.get("theme"));
store.delete("theme");
console.log(store.has("theme"));

What are Cookies? — cookies go to the server; localStorage persists; sessionStorage lasts for the tab.

How to Explain What are Cookies? to an Interviewer

What is What are Cookies (js intro)?

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

Give one small example of What are Cookies (js intro).

let for change, const for fixed Small key-value pairs stored by the browser per domain

What mistake do beginners make with What are Cookies (js intro)?

var leak / const reassign Show the fix

Where do you use What are Cookies (js intro)?

a cart script let total = 0