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sudheerj/javascript-interview-questions

★ 27,383JavaScriptAudience · developerComplexity · 1/5ActiveSetup · easy

TLDR

A collection of 1,000 JavaScript interview questions and answers covering core language concepts, from objects and closures to promises and browser APIs.

Mindmap

mindmap
  root((repo))
    What it covers
      Core language concepts
      Browser APIs
      Async patterns
      Advanced topics
    How to use it
      Self-study guide
      Quick reference
      Interview prep
    Question types
      Beginner level
      Intermediate level
      Advanced level
    Key topics
      Objects and prototypes
      Closures and scope
      Promises and callbacks
      Storage and workers

Things people build with this

USE CASE 1

Study for a front-end developer job interview by working through 1,000 questions organized by topic difficulty.

USE CASE 2

Look up how a specific JavaScript concept works (closures, prototypes, promises) when you need a quick explanation.

USE CASE 3

Brush up on core language fundamentals before a technical interview or when switching to a JavaScript-heavy role.

Tech stack

JavaScript

Getting it running

Difficulty · easy Time to first run · 5min
License could not be detected automatically. Check the repository's LICENSE file before use.

In plain English

This repository is a collection of 1,000 JavaScript interview questions and answers, organized as a structured study guide for anyone preparing for a front-end developer job interview. JavaScript is the programming language that powers interactive behavior on websites, and technical interviews for developer roles typically test deep knowledge of how it works under the hood. The questions cover core JavaScript concepts, things like how objects, prototypes, and closures work, what promises and callbacks are (ways to handle actions that take time, like loading data), how browser storage (cookies, localStorage, sessionStorage) functions, what service workers do, and many more foundational topics. The table of contents alone lists hundreds of topics ranging from beginner to advanced. You would use this as a self-study reference when preparing for technical interviews, or as a quick-lookup resource for specific JavaScript concepts you need to understand or explain. It is useful for aspiring developers, those transitioning into JavaScript roles, or experienced developers brushing up on concepts. Topics also touch on frameworks mentioned in the project topics, the README is longer than what was provided, so additional content likely covers more advanced ground.

Copy-paste prompts

Prompt 1
I'm preparing for a JavaScript interview. Walk me through the difference between closures and scope using examples from this repo's questions.
Prompt 2
Explain how promises and callbacks work in JavaScript, and show me common interview questions about async patterns.
Prompt 3
What are the key differences between localStorage, sessionStorage, and cookies? Give me interview-style Q&A.
Prompt 4
I need to understand prototypes and object inheritance in JavaScript. What are the most important concepts to know for an interview?
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