Feb 5, 2023


JavaScript Interview Questions

When you're ready to hire someone new for your team, it's important to think about what questions you should ask during the interview. You want to focus on the questions that are most relevant for your team and role you're hiring for, so you can understand how candidates will use their skills and experience to contribute to your company.

Look for someone with different areas of expertise from your own—this way, you can supercharge your team and get more done!

What Are the Questions Asked in an JavaScript Interview?

Sitting someone down for an interview is often stressful and difficult, but with some preparation ahead of time you can make it much easier to find the right person for your team.

We’ve put together a list of JavaScript interview questions that will help you evaluate candidates and determine whether they’re a good fit for your team.

Below are the JavaScript interview questions we've had the most success with over the years. They're meant to be used as a guide. You can add your own questions and tweak them as needed.

  • How can you share code between files?

  • What is the definition of a higher-order function?

  • Explain event delegationWhat's the difference between feature detection, feature inference, and using the UA string?

  • Explain the difference between mutable and immutable objects.

  • What is the difference between == and ===?

  • How do you organize your code? (module pattern, classical inheritance?)

  • What are the pros and cons of using Promises instead of callbacks?

  • Explain 'Function.prototype.bind'.Explain the same-origin policy with regards to JavaScript.

  • What are the differences between variables created using let, var or const?

  • Why you might want to create static class members?

  • What's the difference between a variable that is: null, undefined or undeclared? How would you go about checking for any of these states?

  • Explain 'hoisting'.

  • Explain the difference between synchronous and asynchronous functions.

  • Why is extending built-in JavaScript objects not a good idea?

  • Explain how 'this' works in JavaScript

  • What is a closure, and how/why would you use one?

Interview Scorecard Templates by InterviewTime

To save everyone's time, InterviewTime has created a list of templates available for you to use as-is or as inspiration for creating your own interview scorecard template based on what information will be useful for hiring in your company!

To learn more about scorecards, check out our article - Interview scorecard: pros & cons.

Keep all interview assets in one place. Make your interview process consistent.