Question 1

What is the difference between var, let, and const?

Accepted Answer

var is function-scoped and hoisted to undefined; let and const are block-scoped and sit in a temporal dead zone until declared; const additionally prevents reassignment of the binding.

Question 2

What is the difference between the microtask queue and the macrotask queue?

Accepted Answer

The microtask queue holds Promise callbacks and is fully drained after every macrotask (like a setTimeout callback) finishes, which is why a resolved promise's .then runs before a setTimeout(fn, 0).

⚡ JavaScript & Frontend DeveloperInterview Questions

⚡ JavaScript & Frontend Developer
Interview Questions