November 2021

1. What is Node.js? React is an open-source frontend JavaScript library which is used for building user interfaces especially for single page applications. It is used for handling view layer for web and mobile apps. React was created by Jordan Walke, a software engineer working for Facebook. React was first deployed on Facebook’s News Feed […]

1. How to create a simple server in Node.js that returns Hello World? Step 01: Create a project directory mkdir myapp cd myapp Step 02: Initialize project and link it to npm npm init This creates a package.json file in your myapp folder. The file contains references for all npm packages you have downloaded to

1. What is Node.js Process Model? Node.js runs in a single process and the application code runs in a single thread and thereby needs less resources than other platforms. All the user requests to your web application will be handled by a single thread and all the I/O work or long running job is performed

1. What is Node.js? Node.js is an open-source server side runtime environment built on Chrome’s V8 JavaScript engine. It provides an event driven, non-blocking (asynchronous) I/O and cross-platform runtime environment for building highly scalable server-side applications using JavaScript. 2. What are the benefits of using Node.js? From a web server development perspective Node has a

1. What is event bubbling? Event bubbling is a type of event propagation where the event first triggers on the innermost target element, and then successively triggers on the ancestors (parents) of the target element in the same nesting hierarchy till it reaches the outermost DOM element. Example: If you click on EM, the handler

1. What is Hoisting in JavaScript? /*Example 01: Variable Hoisting*/ console.log(message); // output : undefined var message = "The variable Has been hoisted"; /*The above code looks like as below to the interpreter,*/ var message; console.log(message); message = "The variable Has been hoisted"; /*Example 02: Function Hoisting*/ function hoist() { a = 20; var b

1. What is difference between document.getElementById() and document.querySelector()? document.getElementById(): Returns an element object representing the element whose id property matches the specified string. Since element IDs are required to be unique if specified, they’re a useful way to get access to a specific element quickly.element = document.getElementById(id);document.querySelector(): Returns the first matching Element node within the