Web Programming Frontend Frameworks and Tools

Question 1

What is the virtual DOM in React?

Accepted Answer

A lightweight in-memory representation of the real DOM used to optimize updates

Answer

React's virtual DOM is an in-memory JavaScript object tree that mirrors the real DOM, allowing React to calculate minimal updates before applying them to the real DOM.

Question 2

In React, what is JSX?

Accepted Answer

A syntax extension allowing HTML-like code in JavaScript files

Answer

JSX is a syntax extension for JavaScript that looks like HTML and is used in React to describe what the UI should look like, compiled to JavaScript by Babel.

Question 3

What does npm stand for?

Accepted Answer

Node Package Manager

Answer

npm stands for Node Package Manager, the default package manager for Node.js used to install, share, and manage JavaScript dependencies.

Question 4

What is the purpose of a package.json file in a web project?

Accepted Answer

To define project metadata, scripts, and dependencies

Answer

The package.json file is the manifest for a Node.js project, containing metadata like name, version, scripts, and the list of dependencies.

Question 5

What is the main purpose of a CSS preprocessor like SASS?

Accepted Answer

To extend CSS with variables, nesting, and mixins for better maintainability

Answer

CSS preprocessors like SASS add programming features to CSS such as variables, nesting, mixins, and functions, which are then compiled down to standard CSS.

Web Programming Practice Test

Web Programming Practice Test

Web Programming Frontend Frameworks and Tools