Node.js Certification Course

Node JS is not a programming language but an interpreter or a run time environment in JavaScript. It is better to say that it is a language engine that allows to run a code locally on a computer. 

The challenge of learning Node JS totally depends on the expertise of the person learning it. A good mathematician with knowledge about any programming language master it fast ,and even an experienced programmer can have a hard time learning the run time environment. 

Node JS is a JavaScript runtime environment while Python is a programming language. We cannot directly compare them so we compare JavaScript runtime with Python on the backend. Both of them go neck-on-neck in terms of scalability, concurrency and error handling but the one area where Python cannot match Node JS is in terms of performance. Node JS is  based on Google Chrome’s V8 engine so it provides significantly better performance. 

Steps to run Node JS code: 

• Find Command Prompt by entering cmd in the search bar. Select cmd in the search results menu to open Command Prompt.  
• Type the command below and then press “Enter” in order to create a file name “test-node.js” which contains a simple application to print the result of 1 + 1: 

echo console.log(1+1); >> test-node.js 

• Type node followed by the name of the application, given above and then press “Enter”: 

node test-node.js 

• The result of running the application should be printed out in the command prompt. 

Node JS is a runtime environment in JavaScript that can be used in both types of scenarios: 

Front-end javascript finds the JS under HTML5 pages, where it is used to build non-static web pages and automatically react to events that occur on the page, whereas back-end JS is used with node.js and its corresponding packages to handle data transfers, web page requests, and general server tasks. 

Yes, Node JS will be able to run Web Assembly although the performance may be affected. It can be run either on client-side or server-side. 

Callback is a function that is passed to another function so that the action can take place “asynchronously” meaning “not existing or occurring at the same time”. Callback hell occurs when you have callbacks within callbacks within callbacks in the code and it is not possible to get an output or result. 

Node in Node JS stands for a single node that is used to handle multiple concurrent clients. The platform is called “Single Threaded Event Loop”. This process along with the V8 engine makes Node JS very fast. 

Here are some of the best Node JS frameworks: 

• Express.js - On top of a set of routing libraries, it provides a few web application features 
• Socket.io - It is designed to establish real-time two-way event-based communication. 
• Sails.js - It is used for developing modern, real-time features like chat. 

While writing a code in JavaScript, it is very important to structure it properly. Node.js modules can be thought of as JavaScript libraries where you would want some parts to be together and some parts to be completely separated from rest of the code. Each module has its own scope and cannot interfere with other modules and pollute the rest of the code. 

Here are some types of apps that can be built with Node JS: 

• Online payment applications 
• Microservices architecture 
• Social Platforms 
• Streaming Platforms 
• E-commerce platforms 
• Internet of Things 

Depending on what you want your application to do, here are some examples of scaling and what they are used for:  

• Horizontal scaling: Duplicating your application so as to cope with large number of incoming connections. 
• Vertical scaling: Used to enhance power and increase memory. 
• Have multiple processes running on the same machine to distribute the incoming connections. 
• Scaling Across Multiple Machines with Network Load Balancing where each machine will run one or more processes in order to balance the load across the entire system. 

At first, import the ‘data_base’ using the following statement: 

let data_base = require('database'); 

Secondly, establish a connection to the database by calling the createConnection() method and provide information on data_base server such as host, user, password and database as follows: 

let connection = data_base.createConnection({host: 'localhost' ,user: 'root' ,password: ' ', database: 'todoapp'}); 

Here, we created a connection to todoapp database in the local database server. 

Now, call the connect() method on the connection object to connect to the data_base database server: 

connection.connect(function(err) { 

  if (err) {  return console.error('error: ' + err.message); } 

  console.log('Connected to the data_base server.'); 

}); 

The connect() method accepts a callback function that has the err argument which provides the detailed error if any error occurred. 

If the program shows the following result, the program is successful: 

> node connect.js 

Connected to the data_base server 

Before creating Node JS, the browsers were the only place where we could run JavaScript application because they contained the JavaScript engine  like Google's V8 engine and Firefox's Spidermonkey. In order to be able to run JavaScript on your computer or any kind of robotic device you need to have Node JS. Johnny-5 is a JavaScript library that you can use with Node JS. if you have Raspberry Pi. You can build robotic functions using JavaScript. Node JS is really fast in nature and more companies are using it now as a back-end server because of it is built quality. 

First of all, you can start learning JavaScript because Node.JS is nothing but a part of JavaScript. As far as my experience I would advise you to strengthen your basic concepts and start building small projects. By building small projects your conceptions, you will have a clear understanding and gain some experience. Once you get a proper hold on the basic concepts you can refer to Stack Overflow which will give you real insights about the issues people face during programming in Node.JS. Once you are done with all of this, you can start building a full-stack project using Note JS. 

Node.JS is a fast, responsive, high-throughput server side platform. Major companies like LikedIn, NASA, Facebook make use of it to build their products and future innovations. 

Node.JS is a very good choice for future web implementations because of the following-  

• It is easy to learn and most of the developers learn by self-tutoring.  
• It is one of the fastest growing JavaScript frameworks over the past few years because of its various implementations and popularity  
• It enhances the productivity, performance of the application and the satisfaction level of Developers and reduces the cost and time taken for process development 

Most of the famous companies use Node JS.Some of the popular companies that uses Node.js and other JavaScript-based frameworks - 

• Flipkart 
• Hacker Rank 
• Netflix 
• Uber 
• SO 
• Linkedin 
• Walmart 
• NASA 
• Paytm 
• Medium 
• eBay