Extending Error in JavaScript

To extend the built-in Error object in JavaScript, you can define a subclass of Error using the extends keyword. This allows you to create custom errors with additional properties or methods.

In ES6, you can define a custom error class as follows:

class MyError extends Error {
  constructor(message) {
    super(message);
    this.name = 'MyError';
  }
}

This class inherits the properties and methods of the Error class, and adds a custom name property. You can throw an instance of this custom error using the throw keyword:

throw new MyError('An error occurred');

The resulting error will be an instanceof Error, but it will also have the additional name property. This allows you to handle custom errors differently in your code, if needed.