MEAN Stack Interview Questions and Answers
1Q) What’s the MEAN Stack?
2Q) What is Express?
Ans: Express is one the most prevalent and generally utilized web systems in Node.js advancement zone. Express is a negligible web server based on Node.js that gives all the basic usefulness required for conveying web applications to the program and cell phones. ExpressJS enables you to deal with Routes, Server, and I/O stuff effortlessly.
3Q) What is Node.js?
4Q) What is DATA Modeling?
Ans: Data modeling, in the context of Mongoose and MongoDB, is defining what data can be in a document, and what data must be in a document. When storing user information you might want to be able to save the first name, last name, email address, and phone number. But you only need a first name and email address, and the email address must be unique. This information is defined in a schema, which is used as the basis for the data model.
5Q) What are the features of Node.js?
Learn MeanStack by Tekslate - Fastest growing sector in the industry. Explore Online " MeanStack Training" and course is aligned with industry needs & developed by industry veterans. Tekslate will turn you into MeanStack Expert.
6Q) Why is consistent style important and what tools can be used to assure it?
Ans: Consistent style helps team members modify projects easily without having to get used to a new style every time. Tools that can help include Standard and ESLint.
7Q) What is the difference between AngularJS and Node.js?
Ans: Angular.JS is a web application development framework while Node.js is a runtime system.
8Q) What Is Mongoose?
Ans: Mongoose is an Object Document Mapper (ODM). This means that Mongoose allows you to define objects with a strongly-typed schema that is mapped to a MongoDB document.
9Q) What Are The Key Features Of Node.Js?
Ans: -Asynchronous event-driven IO helps concurrent request handling – All APIs of Node.js are offbeat. This component implies that if a Node gets a demand for some Input/Output activity, it will execute that task out of sight and proceed with the preparation of different solicitations. Accordingly, it won't sit tight for the reaction from the past solicitations.
-Single-Threaded yet Highly Scalable – Node.js utilizes a solitary string model for occasion circling. The reaction from these occasions could conceivably achieve the server quickly. In any case, this does not piece different activities. In this way making Node.js exceptionally adaptable. Customary servers make restricted strings to deal with demands while Node.js makes a solitary string that gives administration to significantly bigger quantities of such demands.
-There is an active and energetic group for the Node.js system – The dynamic group dependably keeps the structure refreshed with the most recent patterns in the web advancement.
-No Buffering – Node.js applications never support any information. They essentially yield the information in pieces.
10Q) Explain REPL In Node.Js?
Ans: The REPL stands for “Read Eval Print Loop”. It is a simple program that accepts the commands, evaluates them, and finally prints the results. REPL provides an environment similar to that of a Unix/Linux shell or a window console, in which we can enter the command and the system, in turn, responds with the output. REPL performs the following tasks.
EVAL- It Executes the data structure.
PRINT- It Prints the result obtained after evaluating the command.
LOOP- It Loops the above command until the user presses Ctrl+C two times.
11Q) What Is The Difference Between Nodejs, AJAX, And JQuery?
Node.Js – It is a server-side platform for developing client-server applications. For example, if we're to build an online employee management system, then we won’t do it using client-side JS. But the Node.js can certainly do it as it runs on a server similar to Apache, Django not in a browser.
12Q) What's the difference between operational and programmer errors?
Ans: Operation errors are not bugs, but problems with the system, like request timeout or hardware failure.
On the other hand programmer errors are actual bugs.
13Q) What's a test pyramid? How might you actualize it when discussing HTTP APIs?
Ans: A test pyramid portrays that when works test cases there ought to be significantly more low-level unit tests than abnormal state end-to-end tests.
When discussing HTTP APIs, it might come down to this:
Plenty of low-level unit tests for your models
Less joining tests, where your test how your models collaborate with each other
Significantly fewer acknowledgment tests, where you test the genuine HTTP endpoints
14Q) Explain callback in Node.js?
Ans: A callback work is called toward the culmination of a given errand. This enables other code to keep running meanwhile and keeps any blocking. Being an offbeat stage, Node.js intensely depends on callback. All APIs of Node is composed to help callbacks.
15Q) What does event-driven programming mean?
Ans: In PC programming, occasion driven writing computer programs is a programming worldview in which the stream of the program is controlled by occasions like messages from different projects or strings. It is an application engineering method separated into two segments 1) Event Selection 2) Event Handling
16Q) Explain REPL In Node.Js?
Ans: The REPL stands for “Read Eval Print Loop”. It is a simple program that accepts the commands, evaluates them, and finally prints the results. REPL provides an environment similar to that of Unix/Linux shell or a window console, in which we can enter the command and the system, in turn, responds with the output. REPL performs the following tasks.
17Q) Is Node.Js Entirely Based On A Single-Thread?
Ans: Yes, it’s true that Node.js processes all requests on a single thread. But it’s just a part of the theory behind Node.js design. In fact, more than the single thread mechanism, it makes use of events and callbacks to handle a large no. of requests asynchronously.
To explain it practically, let’s assume there are 100s of requests lined up in the Node.js queue. As per the design, the main thread of the Node.js event loop will receive all of them and forward to background workers for execution. Once the workers finish processing requests, the registered callbacks get notified on the event loop thread to pass the result back to the user.