This content originally appeared on DEV Community and was authored by Deepak Kumar
JavaScript is a crucial skill for any developer, and mastering it can open doors to exciting career opportunities. Whether you're preparing for your first JavaScript interview or aiming to brush up on your skills, here are 100 essential questions that can help you ace your interview:
- What is JavaScript?
- What are the key differences between JavaScript and Java?
- What are the data types in JavaScript?
- Explain the concept of hoisting in JavaScript.
- How does JavaScript handle asynchronous operations?
- What are closures in JavaScript?
- What is the prototype chain in JavaScript?
- How do you check the type of a variable in JavaScript?
- Explain the event bubbling and capturing in JavaScript.
- How does prototypal inheritance differ from classical inheritance?
- What is the difference between
==
and===
operators? - How does
setTimeout
function work in JavaScript? - Explain the concept of promises in JavaScript.
- What are arrow functions in JavaScript?
- How does
this
keyword work in JavaScript? - What is the use of
bind
method in JavaScript? - How can you create a closure in JavaScript?
- What is the difference between
null
andundefined
? - Explain the concept of event delegation in JavaScript.
- What is the difference between synchronous and asynchronous JavaScript?
- How do you handle errors in JavaScript?
- What are higher-order functions in JavaScript?
- Explain the difference between function declaration and function expression.
- How can you achieve inheritance in JavaScript?
- What are the different ways to declare a variable in JavaScript?
- Explain the use of
map
,filter
, andreduce
functions. - What is the purpose of
JSON.stringify
andJSON.parse
in JavaScript? - How can you prevent the default behavior of an event in JavaScript?
- Explain the concept of memoization in JavaScript.
- What are the different types of scopes in JavaScript?
- How does the ES6 module system differ from CommonJS?
- What are the rest parameters in JavaScript?
- How do you handle CORS in JavaScript?
- Explain the use of
async
andawait
in JavaScript. - What are generator functions in JavaScript?
- How can you convert a callback-based function to a promise-based function?
- Explain the concept of currying in JavaScript.
- What is the difference between
let
,const
, andvar
in JavaScript? - How can you detect if a variable is an array in JavaScript?
- Explain the purpose of the
Symbol
data type in JavaScript. - What is a closure trap in JavaScript?
- How do you handle memory leaks in JavaScript?
- Explain the use of
try
,catch
, andfinally
in error handling. - What is the purpose of the
use strict
directive in JavaScript? - How can you check if an object has a property in JavaScript?
- Explain the concept of event loop in JavaScript.
- What are the differences between
forEach
andmap
methods? - How can you copy an object in JavaScript?
- Explain the differences between
slice
andsplice
methods. - What is the purpose of the
WeakMap
andWeakSet
in JavaScript? - How can you merge two arrays in JavaScript?
- Explain the purpose of the
Symbol.iterator
method in JavaScript. - What are the different ways to create an object in JavaScript?
- How can you validate an email address in JavaScript?
- Explain the purpose of the
includes
method in arrays. - What are the differences between
==
and===
operators in JavaScript? - How can you create a private variable in JavaScript?
- Explain the purpose of the
Object.keys
method in JavaScript. - What are the differences between
null
,undefined
, andundeclared
in JavaScript? - How can you convert a string to a number in JavaScript?
- Explain the purpose of the
Array.isArray
method in JavaScript. - What are the differences between function declaration and function expression in JavaScript?
- How can you convert JSON to a JavaScript object?
- Explain the purpose of the
Array.prototype.map
method in JavaScript. - What are the differences between
let
,const
, andvar
in JavaScript? - How can you sort an array of objects by a specific property in JavaScript?
- Explain the purpose of the
Array.prototype.filter
method in JavaScript. - What are the differences between
==
and===
operators in JavaScript? - How can you remove duplicates from an array in JavaScript?
- Explain the purpose of the
Array.prototype.reduce
method in JavaScript. - What are the differences between
null
,undefined
, andundeclared
in JavaScript? - How can you check if a string contains a substring in JavaScript?
- Explain the purpose of the
Array.prototype.forEach
method in JavaScript. - What are the differences between
let
,const
, andvar
in JavaScript? - How can you reverse a string in JavaScript?
- Explain the purpose of the
Array.prototype.indexOf
method in JavaScript. - What are the differences between
==
and===
operators in JavaScript? - How can you find the largest and smallest numbers in an array in JavaScript?
- Explain the purpose of the
Array.prototype.some
method in JavaScript. - What are the differences between
null
,undefined
, andundeclared
in JavaScript? - How can you capitalize the first letter of a string in JavaScript?
- Explain the purpose of the
Array.prototype.every
method in JavaScript. - What are the differences between
let
,const
, andvar
in JavaScript? - How can you remove falsy values from an array in JavaScript?
- Explain the purpose of the
Array.prototype.slice
method in JavaScript. - What are the differences between
==
and===
operators in JavaScript? - How can you flatten an array in JavaScript?
- Explain the purpose of the
Array.prototype.sort
method in JavaScript. - What are the differences between
null
,undefined
, andundeclared
in JavaScript? - How can you shuffle an array in JavaScript?
- Explain the purpose of the
Array.prototype.reverse
method in JavaScript. - What are the differences between
let
,const
, andvar
in JavaScript? - How can you find the intersection of two arrays in JavaScript?
- Explain the purpose of the
Array.prototype.join
method in JavaScript. - What are the differences between
==
and===
operators in JavaScript? - How can you find the union of two arrays in JavaScript?
- Explain the purpose of the
Array.prototype.splice
method in JavaScript. - What are the differences between
null
,undefined
, andundeclared
in JavaScript? - How can you create a random number between two numbers in JavaScript?
- Explain the purpose of the
Array.prototype.concat
method in JavaScript.
These questions cover a wide range of topics and are designed to help you solidify your understanding of JavaScript concepts. Make sure to practice answering them and understand the underlying principles to confidently tackle any JavaScript interview. Good luck!
This content originally appeared on DEV Community and was authored by Deepak Kumar
Deepak Kumar | Sciencx (2024-06-17T02:14:49+00:00) Get Ready for Your JavaScript Interview: Top 100 Questions to Practice. Retrieved from https://www.scien.cx/2024/06/17/get-ready-for-your-javascript-interview-top-100-questions-to-practice/
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