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Hidayt Rahman
Hidayt Rahman

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Popular JavaScript Interview Questions

Basic Questions

DOM Questions

  • How to select all element using class?
  • What querySelector() returns?
  • How to find an element in the tree?
  • How to select top most parent element?
  • How to select next element?
  • How to remove element?
  • How to add attribute?
  • How to select a data attribute?
  • How to set value on the data attribute?
  • How to apply style on element?

Demandable Questions

  • What is closure?
  • What is hoisting?
  • What is Higher Order Function?
  • What is Pure Function?
  • What is Recursion?
  • Where we should use Recursion?
  • What is reduce function?
  • What is map function?
  • What is filter function?
  • Difference between == and ===?
  • What is the difference between call, apply and bind?
  • What is the difference between map and forEach

Basic DS and Algo

  • Calculate the functional arguments?
  • Find the largest number?
  • Return the unique numbers from the array?
  • Return the duplicate numbers from the array?
  • Return the count of duplicate numbers from the array?
  • Find the falsy values and return them?
  • compare two arrays and returns true if both are same.
  • compare two objects and return true if both are same.
  • return flat array from the multi dimensional zig-zag array?

Advance Questions

  • What is function Curry?
  • How and where we can use function curry?
  • What is Debounce in JavaScript?
  • What is throttling in JavaScript?
  • Difference between throttling and debouncing?
  • What is event capturing and how we use?
  • What is event bubbling and how we use?
  • What is event delegation and how we use?
  • What is Event Loop?
  • How event loop works?
  • Is JavaScript multi-thread?
  • What is temporal dead zone?

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