How can I create custom error classes in TypeScript?

How can I create custom error classes in TypeScript?

You can create custom error classes in TypeScript by extending the built-in Error class. Here's a simple example:

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

This allows you to throw and catch specific errors in your application.

What if I want to add additional properties to my custom error?

You can add additional properties by defining them in your custom error class. For example:

class CustomError extends Error {
    public code: number;
    constructor(message: string, code: number) {
        super(message);
        this.name = 'CustomError';
        this.code = code;
    }
}

Now you can include a code when you throw the error.

Can I use my custom error in a try-catch block?

Absolutely! You can catch your custom error like this:

try {
    throw new CustomError('Something went wrong', 404);
} catch (error) {
    if (error instanceof CustomError) {
        console.error(`Error: ${error.message}, Code: ${error.code}`);
    }
}

Are there any best practices for using custom errors?

Yes, some best practices include:

1. Always set the name property to the name of your custom error class.
2. Use meaningful messages and codes.
3. Ensure your custom errors are properly documented for other developers.