JavaScript Interview Questions and Answers

If you have a JavaScript interview coming up soon then it's time for you to prepare for it. Don't expect to answer only technical questions. Interviewers will also want to know about yourself, your previous jobs and experiences.

[caption id="attachment_1136" align="aligncenter" width="712"] JavaScript Interview Questions[/caption]

Programming Interview Questions

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JavaScript Interview Questions

• What is the difference between '==' and '===' in JavaScript?


• What is a closure in JavaScript?


• Given five large tech companies Google, Microsoft, IBM Apple and Tesla which one would you  least want to work?


• Why are you leaving your current job?


• Why do you want to work for us?


• Why should we hire you?


• How long have you been working as a JavaScript developer?


• What is your experience?

You will be asked lots of questions about React lifecycle, algorithm and data structure.

• Do you know how to play Rock, Paper, Scissors?

Solve the following: function multiply(x,y){return x * y}; So multiply(3,5) returns 15. What changes do we have to make to multiply so we can write multiply(3)(5);

• What is the difference between var and let closure property, ES6 in JavaScript?


• What are your biggest completed projects?


• Tell me about yourself.


• Tell me about your previous projects.


• What is encapsulation in OOP used for?


• What happens when you connect to an SSL socket?


• What is 'this' in JavaScript?


• How could you have simplified aspects of the technical test?


• Describe an interesting technical problem you have had to solve and the solution?


• What digital product do you admire?


• How should product and tech work together to deliver?


• How would you speed up a slow website?


• What status code 401 stands for?


• What motivates you?


• Which one you choose and why? Angular or React?


• What is the difference between null and undefined?


• Could you tell me more about yourself?

There is a huge demand for JavaScript developers in the UK. It's not too difficult to learn JavaScript. Even beginner level JavaScript coders can find a job and make themselves learn more about coding with JavaScript within the company.

Salaries are starting from £60-70k a year and it goes up to over £100k for senior developers with a working history.

We have listed most asked JavaScript interview questions here. You may be asked many questions from the list above however you may be asked questions completely different from this page so better be prepared with other questions too.

There are typical interview questions that you might be asked too such as:

- Why should we hire you?
- What makes you different from other candidates?
- What motivates you?
- Where do you see yourself in 5 years?
- Why did you leave your last job?
- What do you know about us?