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

Copies enumerable properties from source objects into a target.

Object.assign()

  • Object.assign() 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.assign().
  • From the example next to this theory: Copies enumerable properties from source objects into a target.
  • Trap: copying nested objects by accident (shallow copy). Fix that before you talk about advanced JS.
  • Viva: what is Object.assign()? Then show const { name } = student. Then name the trap.

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

Code Examples for Object.assign()

Object.assign() — working example

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

How to Explain Object.assign() to an Interviewer

What is Object.assign()?

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

Give one small example of Object.assign().

const { name } = student Copies enumerable properties from source objects into a target

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

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

Where do you use Object.assign()?

a student record { name, marks }