Question Bank
133 approved questions from the community
What is the primary difference between `.call()` and `.apply()`?
What is the key difference between `<script async>` and `<script defer>` for external scripts?
What determines the value of `this` in a regular function call (non-arrow, non-method)?
Event delegation involves attaching an event listener to a parent element instead of individual child elements.
In the JavaScript event loop, how are microtasks handled relative to macrotasks?
Which modern techniques can center a block-level element both horizontally and vertically?
What is margin collapsing and how can it be prevented?
When would you use the universal selector `*` and the adjacent sibling combinator `+`?
Which combinator selects direct children and which selects any descendant?
What are pseudo-elements like ::before and ::after used for?
Why use a CSS reset (or normalize) at the start of a stylesheet?
What are CSS pseudo-classes used for?
After calling a `useState` setter, what should you expect?
Reconciliation is React's diffing process to decide what to update in the UI.
Copying props into state without clear need can create anti-patterns.
Render props pattern means a component receives:
Why might SSR improve perceived performance?
For async fetching in React, what helps avoid stale response bugs?
What does one-way data flow in React imply?
What is code splitting mainly intended to improve?