What is JavaScript primarily used for? - Answers JavaScript is primarily used for adding
interactivity and dynamic behavior to websites, such as handling user events, manipulating the
DOM, and making asynchronous requests.
What are JavaScript's two main types of data structures? - Answers JavaScript's two main data
structures are objects (used for storing keyed collections) and arrays (used for ordered lists of
values).
What is JavaScript? - Answers A versatile, high-level programming language primarily used for
web development to create interactive effects within web browsers.
What is ECMAScript? - Answers The standard upon which JavaScript is based, with updates that
influence JavaScript's features and syntax.
What are JavaScript closures? - Answers Functions that retain access to their lexical scope,
even when the function is executed outside that scope.
What is the difference between `var`, `let`, and `const` in JavaScript? - Answers `var` is function-
scoped, `let` and `const` are block-scoped, with `const` being immutable after declaration.
What are JavaScript promises? - Answers Objects representing the eventual completion (or
failure) of an asynchronous operation, allowing for more readable async code.
What is the purpose of async/await in JavaScript? - Answers To handle asynchronous
operations in a more synchronous and readable manner using promises.
What is a JavaScript callback function? - Answers A function passed into another function as an
argument, executed after the outer function completes.
What is a JavaScript arrow function? - Answers A shorthand way to write functions, which also
lexically binds the `this` value.
What is the DOM in JavaScript? - Answers The Document Object Model, a programming
interface for web documents that represents the page so that programs can change the
document structure, style, and content.
What is event delegation in JavaScript? - Answers A technique for handling events efficiently by
using a single event listener to manage all child elements.
What is React? - Answers A JavaScript library for building user interfaces, especially for single-
page applications, by using components.
Who created React? - Answers React was developed by Facebook, now Meta, and released in
2013.