Approach to create Custom Error Handler

• The first middleware simulates an error by throwing an exception.
• The second middleware is the custom error handling middleware, which takes four parameters (err, req, res, next).
• Extend the “Error” class to create a custom error class.
• Place the error-handling middleware at the end of the stack.
• Inside the custom error handling middleware, log the error, check its type, and send an appropriate response based on the you defined.

Syntax to create Custom Error Handler Middleware:

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

Error handling is one of the crucial part while building applications. In Express JS middleware functions can be used to handle errors effectively. In this article, we will learn How to create custom error-handling middleware in Express.