Javascript is a popular language which is used by millions of developers around the world and this makes the learning curve easier to learn Node.js both by Javascript developers and complete beginners. Node.js is one of the most sought out skills with a lucrative salary for developing web applications. Becoming proficient in Node.js is also important to become a MEAN<\/a> or MERN stack developer.<\/p>\r\n Get prepared with most frequently asked but important interview questions to prepare yourself for this high paying job<\/a> position. This blog gives you a set of 101 Important Node.js Questions and answers and these questions have been compiled to help both freshers and experienced candidates. We wish you all the best for your Interview!!<\/p>\r\n \r\n Node.js can be used for Real-time web applications, Network Applications, Distributed Applications and for any General Applications<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Node.js works on V8 Virtual Machine Environment which uses Javascript as its Scripting Language<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n It is a Programming Paradigm where the events like Messages or threads define the flow of the program. This application architecture has two sections \u2013 Event Selection and Event Handling<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Node.js is an Asynchronous, Event-driven based Javascript Run-time. It is designed to build and handle scalable Network Applications.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n The non-blocking I\/O is the prominent feature of Node.js and hence there is no need for Locks. This helps in building reasonably scalable systems.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n There are two types of API functions, they are<\/p>\r\n\r\n Yes. That is the advantage of Node.js as it is designed for asynchronous processing on Single Thread and it is believed that more performance and scalability can be achieved for web loads than typical thread based applications.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n There are two arguments, namely the Task Function and Concurrency Value. These are the commonly asked Node.js Interview Questions and Answers <\/strong>for the Fresher graduates.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n This is a loop which process external events and converts them into callback invocations. So for I\/O Calls, node.js can switch from one request to another.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Node.js is a loop based Server for Javascript which gives the ability to write JavaScript code on the Server to access HTTP Stack, file I\/O, TCP and Databases very easily by the programmers. This feature is gaining attention from Java<\/a> programmers.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Because Node.js overcomes this problem by using the Event based Model instead of Threads based model.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n AJAX is a Client Side technology to update the contents of the page without refreshing and it is executed by the Browser. Whereas Node.js is a Server-Side Javascript technology which is executed by the Server and not by the Browser.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n \r\n The Challenge is to have one Process with One Thread to scale up on Multi Core Server.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n External Libraries can be imported using the \u201crequire\u201d command in Node.js. Example, \u201cvar http=require(\u2018http\u2019)\u201d.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Express Framework is most commonly used with Node.js<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n It is used to handle multiple requests to the node.js Server. Callback Function allows the server to prioritize pending requests first, and call the other Function when it is finished.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n All the async Callbacks are handled by the Event Loop. As node.js is a Single Threaded Event Driven language where Listeners are attached to the events. When the said event is triggered, the Listener executes the Callback we provided. All the Functions are queued in a Loop and will be executed one by one when the response is received.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n It is called Input\/Output and it accesses anything outside of the Application. It is loaded in the memory when the Application is started. These are the commonly asked Node.js Interview Questions for Freshers and Experienced c<\/strong>andidates in an interview.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n No, DOM cannot be accessed from node.js<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Read-Eval-Print-Loop is a virtual environment that comes with node.js. It is an Interactive language Shell used to quickly test simple Node.js\/JavaScript code<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n The Debugger Utility can be used which is included with Node.js. To enable a Breakpoint at a specific position of the code, insert the \u201cdebugger\u201d statement .<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n It is a file which contains all the metadata information about a project. This file is used by the \u201cnpm\u201d to identify the project and install the project and all the dependencies that are listed in this file<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n The most popular Node.js Modules are Express, Async, socket.io, Bower, gulp, grunt and browserify.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n Streams are a type of Pipe which is used to read data from a source and pipe it to a destination. Technically, Stream is an EventEmitter with special Methods. Readable, Writable, Duplex and Transform are the types of Streams.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n \u201creadFile\u201d is an asynchronous method to read files. The \u201creadFileSync\u201d is the same as \u201creadFile\u201d except it reads synchronously. Whereas the \u201ccreateReadStream\u201d will read the file in default chunk size of 64kb.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/i><\/i>Explain Where Node.js can be used?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Can you explain how Node.js works?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> Explain about Event Driven programming??<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> What is Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> Explain the key advantages of using Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>What are the types of API functions in node.js?<\/a><\/h4>\r\n<\/div>\r\n
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<\/i><\/i>Is node.js Single Threaded?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>How Control Flow controls the Function Calls?<\/a><\/h4>\r\n<\/div>\r\n
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<\/i><\/i>Explain the tasks that should be done asynchronously using the Event Loop?<\/a><\/h4>\r\n<\/div>\r\n
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<\/i><\/i>List the arguments of async.queue?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>What is the event loop in Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Why node.js gaining attention from Java Programmers?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Why is there no Blocking of I\/O Operations problem in Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> Explain the Differences between Ajax and Node.js?<\/a><\/h4>\r\n<\/div>\r\n
![\"NodeJS](\"\/wp-content\/themes\/zeft\/images\/nodejs-interview-questions-answers-chennai.jpg\")
<\/a><\/div>\r\n \r\n<\/i><\/i> What is the Challenge in using Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>How to import External Libraries in Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Which is the most commonly used Framework with Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Explain the Callback Function in node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>How Event Loop works in Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>What is the Term I\/O Means in node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> How can you Access DOM in node.js<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Explain about the REPL in node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>How to debug Node.js Application?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>What is the use of \u201cpackage.json\u201d?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>List out some of the most popular Node.js Modules?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i> Explain about \u201cStreams\u201d in Node.js?<\/a><\/h4>\r\n<\/div>\r\n
<\/i><\/i>Compare \u201creadFile\u201d vs \u201ccreateReadStream\u201d?<\/a><\/h4>\r\n<\/div>\r\n