Coding⏱️ 2 min read📅 2026-05-31

How to Fix: How do I create a custom Error in JavaScript?

Error in JavaScript constructor delegation

Quick Answer: Use the `Object.create()` method instead of `apply()` to create a new Error subclass.

To fix the issue with constructor delegation not working in your snippet, you need to set the prototype of the parent class before creating a new instance. The problem lies in the line NotImplementedError.prototype = new Error();, where you're trying to override the prototype of the native Error class.

🛠️ Step-by-Step Verified Fixes

Method 1: Overriding the Prototype Correctly

  1. Step 1: Set the prototype of the parent class to a new instance of the native Error class.
  2. Step 2: Call the constructor using super or apply with the arguments.

💡 Conclusion

By overriding the prototype correctly, you can create a custom Error subclass that inherits from the native Error class. Make sure to use super or apply when creating a new instance of your subclass.

Did this fix your problem?

If not, try searching for specific error codes.

🔍 Search Error Database

❓ Frequently Asked Questions