Question Bank
3705 approved questions from the community
Extending built-in JavaScript objects is generally considered a good practice.
Rest parameters and spread syntax use the same ... notation but serve opposite purposes.
WeakMap and WeakSet allow garbage collection of their keys/elements when there are no other references.
What does NaN stand for?
What does the typeof operator return for an array?
What is the difference between <script>, <script async>, and <script defer>?
How does JavaScript garbage collection work?
What are server-sent events (SSE)?
Why would you create static class members?
What is the difference between mutable and immutable objects?
What does JSON.parse() do?
What are generators in JavaScript?
What is the spread operator used for?
What are JavaScript polyfills used for?
How do you abort a fetch request?
What does AJAX stand for?
Web Workers have access to the DOM.
What is a polyfill?
Generator functions use function* syntax.
Set automatically removes duplicate values.