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  How to handle errors in NodeJS Error handling is an important aspect of any software development, and Node.js is no exception. In Node.js, errors can occur at various points in the application, such as during I/O operations, network requests, and when working with external libraries. Node.js uses the standard JavaScript error handling mechanism, which is based on the try-catch statement and the throw keyword. The try-catch statement allows you to catch and handle errors that occur in a specific block of code, while the throw keyword allows you to raise an error. Here is an example of how to use the try-catch statement to handle errors in a Node.js application: Copy code try { // Some code that may throw an error const result = JSON . parse ( 'invalid json' ); } catch (err) { console . error (err); } In this example, we are trying to parse an invalid JSON string, which will throw a SyntaxError error. The catch block will catch this error and log it to th...

  What is middleware in NodeJS and its uses Middleware is a software that sits between an operating system and application, providing services and resources to the application. In Node.js, middleware refers to functions that have access to the request and response objects, and the next function in the request-response cycle. These functions are used to perform tasks such as logging, authentication, and validation. Node.js has a built-in middleware system called Express.js, which is a popular framework for building web applications. Express.js allows developers to easily define and use middleware functions in their application. To use middleware in an Express.js application, you first need to import the Express module and create an instance of the Express application. Then, you can use the app.use() method to define and add middleware functions to the application. These functions will be executed in the order they are defined, before the final route handling function. For example, ...

  NodeJS express validation you must know Express is a popular Node.js framework for building web applications and APIs. One important aspect of building web applications is data validation, which is the process of ensuring that user input is in the correct format and meets certain requirements. In this blog post, we will discuss how to perform validation in an Express application using the express-validator library. First, let's install the express-validator library by running the following command in the terminal: Copy code npm install express-validator Next, we need to import the library in our Express application and configure it to use the middleware. This is done by adding the following code to our app.js file: Copy code const express = require ( 'express' ); const { check, validationResult } = require ( 'express-validator' ); const app = express (); app. use (express. json ()); app. use (express. urlencoded ({ extended : true })); app. use (express. sta...