JavaScript Interview Questions (Advanced Coding, Tricky, Technical)

Whenever you are preparing for the JavaScript role, you had to go through the entire selection process that involves a list of technical questions too. In this blog for Advanced JavaScript Interview, we have given top 50 questions for your reference. Prepare them well before you appear for the final interview and increase your overall chances of getting hired by the top MNCS worldwide with an attractive salary package too.

JavaScript Interview Questions

To make the learning process easy, we have divided the topic in five popular categories as given below –

  • Common JavaScript Interview Questions
  • Advanced JavaScript Interview Questions
  • JavaScript Coding Interview Questions
  • JavaScript Tricky Interview Questions
  • JavaScript Technical Interview Questions

Through the rest of the blog, we will discuss each category one by one and we will give you a list of popular questions too for each of the category as needed by you.

Common JavaScript Interview Questions

JavaScript is not a new trend in the IT space but it used by website development and software development Companies frequently. The large usage of the technology is the reason why JS developers are so demanded in the development market. Here, is a quick list of common JavaScript Interview Questions for the developer role in the leading organization.

  1. What is JavaScript and how is it different from the Java programming language?
  2. List the common data types in JavaScript.
  3. How can you differentiate the JavaScript and ASP script from each other?
  4. How will you define the negative infinity?
  5. How will you break the JavaScript code in multiple lines?
  6. Who is responsible for developing Java Scripts in a Development Company?
  7. How can you add new elements dynamically in JS?
  8. What is a global variable? Define its scope and the problems associated with global variables?
  9. How will you define a prompt box?
  10. How can you add comments in JS?

Advanced JavaScript Interview Questions

When you are focusing on beginner level then learning common JS interview questions is enough. In case, you wanted to apply for an experienced role then learn these advanced JavaScript Interview Questions to improve your learning.

  1. How can you use “var” in your declaration and when it should not be used?
  2. What is the meaning of the attribute async/defer when they are used along the script tag?
  3. How can you differentiate = = and = = = from each other in JS?
  4. How will you check if a variable is NULL or not?
  5. How will you check If the variable is an object?
  6. What do you mean by scoping in JavaScript?
  7. Explain the meaning of hoisting in JavaScript.
  8. How will you define closures? Explain with example?
  9. What do you mean by the differential inheritance and explain its properties too?
  10. What is the benefit of Strict mode in JS? Give one example too.

JavaScript Coding Interview Questions

The next important category is related to Java code. If you are skilled in writing clear code lines then there are great chances of getting hired by Companies quickly.

  1. How will you either the string is Palindrome or not? Write one function for the same.
  2. What is the meaning of undefined and not defined keywords in JS?
  3. Are there any drawbacks of creating private functions in JS?
  4. How will you empty an array in JavaScript?
  5. How will you check either an object is an Array or not?
  6. How functions are declared in JS? Explain the maximum techniques you have used earlier.
  7. How will you calculate the length of an Array?
  8. How will you merge two arrays in simple steps?
  9. Is it possible to remove the duplicate entries from an array?
  10. Write a program to reverse the strong without using already defined function?

JavaScript Tricky Interview Questions

When you are preparing for JavaScript role, then you should master the common and tricky questions both. Here is a quick list of JavaScript Tricky interview Questions to make the selection process easier and faster.

  1. How will you compare any two objects in JavaScript?
  2. How will you find the maximum value from an Array?
  3. What is an “instance of” operator in JS and how is it used by developers?
  4. How will you set a prefix before everything you log on?
  5. How will you check either given parameters are passed well or not?
  6. How JavaScript passes the parameters, either by value or reference?
  7. How could you implement cache to save calculation time for a recursive Fibonacci function?
  8. How could you cache execution of any function?
  9. How will you implement the animation features in JavaScript?
  10. If you want to use an arbitrary object as value of this, how will you do that?

JavaScript Technical Interview Questions

Here is a list of JavaScript Technical Interview questions for your reference when you are preparing for the interview –

  1. How will you use “This” keyword in JavaScript?
  2. What is the significance of timers in JS and how are they utilized during programming?
  3. How will you submit a form in JavaScript?
  4. How can the style or CSS could be used for JavaScript?
  5. Do JS supports automatic type conversions too?
  6. How can you read and write a File in JavaScript?
  7. Name a few looping structures in JavaScript?
  8. What do you mean by the Variable typing?
  9. How to write a function for the delete operator?
  10. Name a few pop-up boxes available in the JavaScript?

We wish you luck and All the Best for your next JavaScript Interview!