# 10 Interview Questions Every JavaScript Developer Should Know in 2024

DevFeed: [10 Interview Questions Every JavaScript Developer Should Know in 2024](<https://devfeed.tech/articles/10-interview-questions-every-javascript-developer-should-know-in-2024-20711.md>)

Original publisher: [Read original article](<https://medium.com/javascript-scene/10-interview-questions-every-javascript-developer-should-know-in-2024-c1044bcb0dfb?source=rss----c0aeac5284ad---4>)

Author: Eric Elliott

Published: 2023-12-31T01:38:10Z

Content type: tutorial

Language: en

Sources: [Eric Elliot](<https://devfeed.tech/sources/eric-elliot.md>)

Topics: [JavaScript](<https://devfeed.tech/topics/javascript.md>), [Test-driven development](<https://devfeed.tech/topics/tdd.md>), [Functional programming](<https://devfeed.tech/topics/functional-programming.md>)

Tags: [career](<https://devfeed.tech/tags/career.md>), [closure](<https://devfeed.tech/tags/closure.md>), [developer](<https://devfeed.tech/tags/developer.md>), [guide](<https://devfeed.tech/tags/guide.md>), [hiring](<https://devfeed.tech/tags/hiring.md>), [interview](<https://devfeed.tech/tags/interview.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [react](<https://devfeed.tech/tags/react.md>), [tdd](<https://devfeed.tech/tags/tdd.md>), [technology](<https://devfeed.tech/tags/technology.md>), [typescript](<https://devfeed.tech/tags/typescript.md>)

## AI overview

A guide to JavaScript interview questions covering closures, pure functions, test-driven development, and related programming concepts. It also discusses how interviewers may assess learning aptitude alongside technical knowledge.

## Source excerpt

The world of JavaScript has evolved significantly, and interview trends have changed a lot over the years. This guide features 10 essential questions that every JavaScript developer should know the answers to in 2024. It covers a range of topics from closures to TDD, equipping you with the knowledge and confidence to tackle modern JavaScript challenges. As a hiring manager, I use all of these questions in real technical interviews on a regular basis. When engineers don't know the answers, I don't automatically reject them. Instead, I teach them the concepts and get a sense of how well they listen, and learn, and deal with the stressful situation of not knowing the answer to an interview question. A good interviewer is looking for people who are eager to learn and advance their understanding and their career. If I'm hiring for a less experienced role, and the candidate fails all of these questions, but demonstrates a good aptitude for learning, they may still land the job! 1. What is a Closure? A closure gives you access to an outer function's scope from an inner function. When functions are nested, the inner functions have access to the variables declared in the outer function scope, even after the outer function has returned: const createSecret = (secret) => { return { getSecret: () => secret, setSecret: (newSecret) => { secret = newSecret; }, }; }; const mySecret = createSecret("My secret"); console.log(mySecret.getSecret()); // My secret mySecret.setSecret("My new secret"); console.log(mySecret.getSecret()); // My new secret Closure variables are live references to the outer-scoped variable, not a copy. This means that if you change the outer-scoped variable, the change will be reflected in the closure variable, and vice versa, which means that other functions declared in the same outer function will have access to the changes. Common use cases for closures include: Data privacy Currying and partial applications (frequently used to improve function composition, e