Web Programming Web Performance and Optimization

Question 1

What does minification do to JavaScript or CSS files?

Accepted Answer

Removes whitespace, comments, and shortens names to reduce file size

Answer

Minification removes unnecessary characters like whitespace, comments, and newlines and may shorten variable names to reduce file size without changing functionality.

Question 2

What is the purpose of browser caching in web performance?

Accepted Answer

To save copies of resources locally so they don't need to be re-downloaded on repeat visits

Answer

Browser caching stores copies of web resources like images, CSS, and JS on the user's device so they can be loaded from cache on subsequent visits instead of re-downloading.

Question 3

What is lazy loading in web development?

Accepted Answer

Deferring the loading of non-critical resources until they are needed

Answer

Lazy loading defers loading of non-critical resources (like off-screen images or secondary JavaScript) until they are actually needed, improving initial page load time.

Question 4

What does CDN stand for and what is its primary purpose?

Accepted Answer

Content Delivery Network — distributes content across servers geographically closer to users

Answer

A CDN (Content Delivery Network) is a distributed network of servers that delivers web content from locations geographically closer to users, reducing latency.

Question 5

What is the purpose of GZIP compression in web performance?

Accepted Answer

To compress text-based resources like HTML, CSS, and JS before sending them over the network

Answer

GZIP compression reduces the size of text-based resources before transmission, which the browser then decompresses, significantly reducing transfer time and bandwidth.

Web Programming Practice Test

Web Programming Practice Test

Web Programming Web Performance and Optimization