👉 “Top 10 JavaScript Interview Questions Every Developer Should Know in 2025”

#webdev #programming #javascript #interview

Intro:
JavaScript is everywhere — frontend, backend (Node.js), and even full-stack interviews.
In 2025, these 10 classic but tricky questions still dominate coding interviews.

🔹 1. Difference between var, let, and const

Scope, hoisting, and re-declaration rules.

🔹 2. What is a Closure?

Function + lexical environment.

Interview tip: Write a quick code example.

🔹 3. Explain == vs ===

Type coercion vs strict equality.

🔹 4. What are Promises and Async/Await?

Handling asynchronous code.

🔹 5. Event Loop in JavaScript

Call stack, callback queue, microtasks.

🔹 6. Difference between null and undefined

A simple but tricky favorite.

🔹 7. What is Hoisting?

Variables and functions behavior before execution.

🔹 8. Explain Prototypal Inheritance

Key to understanding OOP in JavaScript.

🔹 9. What is the difference between map(), forEach(), filter(), and reduce()?

Practical array method comparisons.

🔹 10. Explain Debouncing and Throttling

Critical for frontend performance optimization.

✅ Final Thoughts

If you can explain these 10 concepts clearly (with examples), you’ll ace JavaScript interview rounds in 2025.

👉 Call to Action:
I’ve created JavaScript interview cheat sheets, example code, and practice problems here:
FullStackPrep.dev – JavaScript Interview Prep Guide

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