Code Playground

Interview Toolkit

codecareer4u

codecareer4u is a modern developer learning platform focused on practical knowledge, structured tutorials, and interview-ready preparation. Our mission is to help developers build strong fundamentals and grow confidently in their careers.

Quick Links

Home Blog Tools Interview Toolkit

Resources

About Us Contact Privacy Policy FAQ

Blog Topics

JavaScript React Frameworks & Libraries Career & Interviews

Connect With Us

Follow us on social media

Instagram

Twitter

© 2026 codecareer4u. All rights reserved.

Creating Custom Error Classes in JavaScript | CodeCareer4u

What is an error in JavaScript?

What are the different types of errors in JavaScript?

What is a syntax error?

What is a runtime error?

What is a logical error?

What is the difference between Error, TypeError, and ReferenceError?

What is try...catch in JavaScript?

How does the try block work?

How does the catch block work?

Can try...catch catch syntax errors?

What is the purpose of the finally block?

Does finally always execute?

Can you nest try...catch blocks?

How do you throw a custom error?

What is the throw statement?

What is the Error object?

What properties does the Error object have?

How do you create custom error classes?

How does error handling work in asynchronous code?

How are errors handled in promises?

How are errors handled with async await?

What is global error handling?

What is window.onerror?

What is unhandled promise rejection?

How do you debug runtime errors?

What are common interview traps related to error handling?

javascript interview questions

Question 18 / 26

Keep going — you're making progress.

How do you create custom error classes?