BeginnerFundamentals
JavaScript Interview Track
Closures, the event loop, prototypes, and every core concept interviewers love to probe.
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Topics in recommended order
Learning path
Follow the stages top to bottom. Nothing is locked — the order is simply what works.
- 1FundamentalsVariables, types, coercion and scoping basics.
- 2Functions & ScopeClosures, `this`, arrows and higher-order functions.
- 3Objects & ArraysDestructuring, spreads and transformation methods.
- 4Async JavaScriptThe event loop, promises and async/await.
- 5DOM & BrowserEvents, delegation and how scripts load.
- 6Advanced JavaScriptPrototypes, debounce/throttle and performance.
Fundamentals
5 questionsBeginnerFundamentals
What's the difference between == and === in JavaScript?
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What are JavaScript's primitive data types and how do they differ from objects?
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Explain hoisting in JavaScript.
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What is the difference between null and undefined?
Not practiced yetPractice thisFunctions & Scope
4 questionsIntermediateFunctions & Scope
What is a closure and when would you use one?
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How do arrow functions differ from regular functions?
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What do call, apply and bind do?
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What are higher-order functions and why do they matter?
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3 questionsBeginnerObjects & Arrays
How does destructuring work for objects and arrays?
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What is the difference between shallow and deep copies, and how do you create each?
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When would you choose map, filter, and reduce?
Not practiced yetPractice thisAsync JavaScript
4 questionsIntermediateAsync JavaScript
Explain the event loop. What does setTimeout(fn, 0) actually do?
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How do promises work? Explain their states and chaining.
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What does async/await do and how should errors be handled with it?
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What was 'callback hell' and how did promises and async/await solve it?
Not practiced yetPractice thisDOM & Browser
2 questionsIntermediateDOM & Browser
What is event delegation and how does event bubbling work?
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What do defer and async attributes do on script tags?
Not practiced yetPractice thisAdvanced JavaScript
2 questionsAdvancedAdvanced JavaScript
What is the difference between debounce and throttle? When do you use each?
Not practiced yetPractice thisAdvancedAdvanced JavaScript