Object.entries() — JS Technical Interview Questions & Answers

Returns an array of [key, value] pairs.

Object.entries()

  • Object.entries() is a JS topic. In plain words you use it for { name, marks } in a student record. Don’t start with a slogan — start with that picture.
  • Smallest example: const { name } = student. Type it, run it, and say what you see. If you can do that from memory, you know Object.entries().
  • From the example next to this theory: Returns an array of [key, value] pairs.
  • Trap: copying nested objects by accident (shallow copy). Fix that before you talk about advanced JS.
  • Viva: what is Object.entries()? Then show const { name } = student. Then name the trap.

Technical Interview Tip: What is Object.entries()? Show this: const { name } = student. Trap: copying nested objects by accident (shallow copy).

Code Examples for Object.entries()

Object.entries() — working example

// Topic: Object.entries()
const nums = [1, 2, 3];
const doubled = nums.map((n) => n * 2);
console.log(doubled);
console.log(doubled.reduce((a, b) => a + b, 0));

Object.entries(): map then reduce on [1, 2, 3]. Say both prints.

How to Explain Object.entries() to an Interviewer

What is Object.entries()?

Used for { name, marks } a student record Not just the heading

Give one small example of Object.entries().

const { name } = student Returns an array of [key, value] pairs

What mistake do beginners make with Object.entries()?

copying nested objects by accident (shallow copy) Show the fix

Where do you use Object.entries()?

a student record { name, marks }