node js interview questions and answers pdf

Node Js Interview Questions And Answers Pdf

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What is Node. Where can you use it? Answer : Node. It is used to build scalable programs especially web applications that are computationally simple but are frequently accessed. You can use Node.

Node Js Interview Questions and Answers for Freshers

Are you a MEAN stack developer and have an interview lined up? This runtime allows executing the JavaScript code on any machine outside a browser this means that it is the server that executes the Javascript and not the browser. It means Node.

It is suitable for environments where multiple people work together. For example, they post their documents, modify them by doing check-out and check-in of these documents. Here again, we have servers that handle thousands of request for downloading advertisements from a central host. And Node. Another ideal scenario to use Node.

Last but not the least, since Node. However, we can use Node. But it is a single threaded framework, so we should not use it for cases where the application requires long processing time. Hence, Node. It is a free, cloud-based IDE that supports, application development, using popular programming languages like Node. It provides a powerful online code editor that enables a developer to write, run and debug the app code.

WebStorm is a lightweight yet powerful JavaScript IDE, perfectly equipped for doing client-side and server-side development using Node. The IDE provides features like intelligent code completion, navigation, automated and safe refactorings.

It is a robust IDE that supports web application development using mainstream technologies like Node. To enable the IDE that can do Node. It provides features, including syntax highlighting, code assistance, code completion and more. We can even run and debug Node. It is a cross-platform IDE that supports development in main programming languages, like Node.

It offers a variety of features, including syntax highlighting, keyboard shortcuts, collapsible Pane, workspace, auto indenting, code folding and code preview using built-in browser. It works on top of Electron framework to develop cross-platform apps using web technologies. Atom comes pre-installed with four UI and eight syntax themes in both dark and light colors. We can also install themes created by the Atom community or create our own if required.

A Node. Whenever Node. An Event Loop is a functionality which handles and processes all your external events and just converts them to a callback function. It invokes all the event handlers at a proper time. While processing a request, Node. Now, whenever its response is ready, an event is called which triggers the associated callback function to send this response. Usually, the delivery boy goes to each and every house to deliver the packet. The problem arises when any one house is not open.

What he will do next, is to call the owner and ask him to call when the house is open. Meanwhile, he is going to other places for delivery.

Instead, it attaches a callback function call from the owner of the house to it. Whenever the processing of a request completes the house is open , an event gets called, which triggers the associated callback function to send the response. To summarize, Node.

It is a simple program that accepts the commands, evaluates them, and finally prints the results. REPL performs the following tasks.

In fact, more than the single thread mechanism, it makes use of events and callbacks to handle a large no. Moreover, Node. JavaScript executes at the server-side by Google Chrome v8 engine.

As per design, the main thread of Node. Once the workers finish processing requests, the registered callbacks get notified on event loop thread to pass the result back to the user. All the APIs of Node. For example, suppose we have a function to read a file, as soon as it starts reading the file, Node.

Once file read operation is complete, it will call the callback function and pass the contents of the file as its arguments. This functionality makes Node. Initially, you may praise Callback after learning about it. Callback hell is heavily nested callbacks which make the code unreadable and difficult to maintain.

In this scenario, Node. But this approach may lead to blocking the entire process if there is a task running longer than expected. So whenever a long-running process finishes its execution, it triggers the callback associated. With this approach, it can allow the code execution to continue past the long-running task. However, the above solution looks extremely promising. But sometimes, it could lead to complex and unreadable code.

More the no. Just see the below example. There are four solutions which can address the callback hell problem. It proposes to split the logic into smaller modules. And then join them together from the main module to achieve the desired result. The caller here is the main method using the async module. Promises give an alternate way to write async code. It takes two optional arguments, both functions. Depending on the state of the promise only one of them will get called.

The first function call proceeds if the promise gets fulfilled. However, if the promise gets rejected, then the second function will get called. Generators are lightweight routines, they make a function wait and resume via the yield keyword. The one common trait between Node. However, they serve completely different purposes. It is a server-side platform for developing client-server applications. But the Node. It is a client-side scripting technique, primarily designed for rendering the contents of a page without refreshing it.

There are a no. This library provides many useful functions to help in JavaScript development. There are three keywords in Node. These are Global, Process, and Buffer. The Global keyword represents the global namespace object. An important point to note about the global objects is that not all of them are in the global scope, some of them fall in the module scope.

Variables declared using the var keyword become local to the module whereas those declared without it get subscribed to the global object. It is also one of the global objects but includes additional functionality to turn a synchronous function into an async callback. There is no boundation to access it from anywhere in the code. It is the instance of the EventEmitter class. And each node application object is an instance of the Process object.

The Buffer is a class in Node. It is similar to a list of integers but stores as a raw memory outside the V8 heap. We can convert JavaScript string objects into Buffers. But it requires mentioning the encoding type explicitly.

Events module in Node. It is accessible via the following code. Stream in Node. In Node. The event thrown by the Stream varies with time. Some of the commonly used events are as follows. NPM comes bundled along with Node. We can verify its version using the following command-. For example, following is the command to install a famous Node. By default, NPM installs any dependency in the local mode.

Node Js Interview Questions And Answers Pdf

Download PDF 1 What is node. It will be loaded into the machine memory to run the program, once the application is started. In computer programming, event driven programming is a programming paradigm in which the flow of the program is determined by events like messages from other programs or threads. It is an application architecture technique divided into two sections 1 Event Selection 2 Event Handling. Web applications especially real-time web apps Network applications Distributed systems General purpose applications 6 What is the advantage of using node. It provides an easy way to build scalable network programs Generally fast Great concurrency Asynchronous everything Almost never blocks 7 What are the two types of API functions in Node. The two types of API functions in Node.

Lesson 7 of 7 By Taha Sufiyan. Although there are a few commonly asked Node. We have compiled a comprehensive list of common Node. This will also help you understand the fundamental concepts of Node. It is used to create server-side web applications. You can also use it for developing: Real-time web applications, Network applications, General-purpose applications, and Distributed systems. A web server using Node.

Download PDF. 1) What is is a Server side scripting which is used to build scalable programs. Its multiple advantages over.

Top Node.js Interview Questions You Must Prepare In 2021

Are you a MEAN stack developer and have an interview lined up? This runtime allows executing the JavaScript code on any machine outside a browser this means that it is the server that executes the Javascript and not the browser. It means Node. It is suitable for environments where multiple people work together. For example, they post their documents, modify them by doing check-out and check-in of these documents.

A list of top frequently asked Node. It runs within the Node. This runtime facilitates you to execute a JavaScript code on any machine outside a browser. It accesses anything outside of your application.

Way back when, Node. However, the callback is not executed immediately at this time, but added to the function queue so that it is executed as soon as possible , after all the currently executing and currently queued event handlers have completed. Setting the delay to 0 adds the callback to the queue immediately so that it is executed as soon as all currently-queued functions are finished.

В тусклом свете мониторов Сьюзан увидела, что это, и побледнела. Он достал пистолет. Он выдвинул два стула на середину комнаты.

 У м-меня его. Беккер покровительственно улыбнулся и перевел взгляд на дверь в ванную.

Он не чувствовал никакой боли - один лишь страх. Пуля ударила в кафельную плитку азульехо чуть сзади. Осколки посыпались вниз и попали ему в шею. Беккер рванулся влево, в другую улочку. Он слышал собственный крик о помощи, но, кроме стука ботинок сзади и учащенного дыхания, утренняя тишина не нарушалась ничем.

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  1. Kai B.

    Preparation is as important as your knowledge for a successful programming interview.

    30.12.2020 at 16:15 Reply
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