JavaScript Interview Cheat Sheet

1. What is JavaScript and where is it used?

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2. Difference between var, let, and const.

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3. What is hoisting in JavaScript?

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4. Difference between synchronous and asynchronous execution.

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5. What is a closure?

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6. What are data types in JavaScript?

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7. Difference between == and ===.

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8. What is the event loop?

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9. Difference between null and undefined.

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10. What are first-class functions?

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11. Difference between function declaration and function expression.

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12. What is the this keyword?

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13. Difference between call, apply, and bind.

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14. What is prototype in JavaScript?

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15. Difference between ES5 and ES6.

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16. What are promises?

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17. Explain async/await.

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18. Difference between shallow copy and deep copy.

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19. What is the difference between let inside and outside loops?

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20. Explain event delegation.

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21. What is the difference between function scope and block scope?

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22. Explain closures with real-world usage.

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23. What is the DOM and how does JavaScript interact with it?

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24. Explain event bubbling and capturing.

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25. Difference between innerHTML, innerText, and textContent.

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26. Explain template literals.

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27. What are arrow functions and how do they differ from regular functions?

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28. Explain higher-order functions.

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29. What is the difference between map, forEach, and filter?

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30. Explain setTimeout vs setInterval.

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31. What is the difference between synchronous and asynchronous DOM manipulation?

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32. Explain promises and chaining.

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33. What are the browser storage options in JavaScript?

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34. Difference between synchronous and asynchronous XHR/fetch.

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35. How do you handle cross-origin requests?

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36. Explain event delegation and its benefits.

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37. Difference between call, apply, and bind.

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38. Difference between == and ===.

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39. Difference between null and undefined.

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40. What are IIFEs (Immediately Invoked Function Expressions)?

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41. Explain ES6 modules and their benefits.

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42. Difference between default export and named export.

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43. Explain template literals and tagged templates.

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44. What are destructuring assignments?

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45. Explain rest and spread operators.

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46. What are default parameters in functions?

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47. Explain arrow functions and lexical this.

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48. Difference between let, const, and var in ES6.

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49. Explain promises and chaining in ES6+.

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50. Explain async/await syntax.

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