Web Development Flashcards

What is the difference between localStorage and sessionStorage in browsers?

Answer: localStorage persists until cleared; sessionStorage clears when the tab closes

localStorage persists indefinitely across sessions, while sessionStorage is cleared when the browser tab or window is closed.

In JavaScript, what does the 'Event Loop' primarily manage?

Answer: Executing callback functions from the task queue when the call stack is empty

The event loop continuously checks if the call stack is empty, then pushes pending callbacks from the queue for execution.

Which HTML element is semantically correct for the main navigation links of a website?

Answer:

The element is the semantic HTML5 landmark element specifically designed for major navigation link sections.

What problem does CSS specificity solve?

Answer: It decides which CSS rule applies when multiple rules target the same element

CSS specificity is a weight system that determines which conflicting rule takes precedence when multiple selectors target the same element.

Which JavaScript Promise method runs all promises in parallel and rejects as soon as any one fails?

Answer: Promise.all()

Promise.all() executes all promises concurrently and short-circuits with a rejection if any single promise rejects.

In a CSS Grid layout, what does 'fr' stand for and represent?

Answer: Fractional unit — a share of the available free space

The fr unit represents a fraction of the leftover free space in the grid container after fixed-size tracks are accounted for.

What is the purpose of the 'viewport' meta tag in HTML?

Answer: Controls how the browser scales and sizes the page on mobile devices

The viewport meta tag instructs mobile browsers on how to scale the layout, commonly set to match the device's width.