Introduction to Node.js

Node.js came into existence when the developers were already using javascript. It is something that is used only to run inside the browser and runs on user's machines as a standalone process. This means that users can create applications by utilizing javascript outside the context of the browser. Node.js has a better feature set when compared with JavaScript, and it is similar to other programming languages like Python, Java, PHP, etc.

A Complete Guide for Node.js

What is Node.js?

Node.js is an open-source, cross-platform server environment, and it enables users to run javascript on the server. JavaScript users can make use of the Node.js environment to deploy the language for scripting on the server-side, while also running scripts to generate the dynamic web page content. 

With node.js web development, event-driven programming methods can be implemented. It also has APIs which are helpful in making interactions with I/O devices. These APIs are used in the development of distributed web applications and high-performance web servers.

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Who created Node.js?

Ryan Dahl has created node.js in 2009 with its initial release developed to support operating systems like Linux and Mac OS X, and later in 2011, the support for windows was added. 

Why is Node.js popular?

Node.js is widely used because of its large, open-source, active, javascript based ecosystem. According to a survey conducted by StackOverFlow in 2018, Node.js is considered as the most widely used development frameworks and JavaScript remains at the top as the most popular language in the table of programming, scripting, and Markup languages. 

Node.js, Javascript, and Python are advancing quickly, whereas languages like PHP and C# are gradually falling out of interest. In the end, JavaScript loses only to Python and remains in second place among the list of most wanted programming languages. Both these languages are competing with each other leaving others behind. And in the case of most popular frameworks, Node.js takes the first place.

What is Node.js used for?

Node.js is basically used for non-blocking, event-driven servers because of its single-threaded behaviour. It is particularly used for traditional websites and back-end application programming interface services. It is designed with real-time and pushed back architectures.

Download Node.js

You can download the latest version (10.15.3) of Node.js source code here

Related Article: Middleware in Node.JS

How node.js processes a file request?

This section shows how Node.js handles a file request through the following steps:

Step1: Pushes the task to the file system of a computer.

Step2: Waits for the next request.

Step3: After the file system has opened and read the file, the server returns the information to the client.

Node.js does not wait, and simply accepts the next request. It runs single threaded, asynchronous programming, non-blocking, which is memory efficient.

Node.js Example:

Creating a basic Node.js application

After the installation of Node.js is completed, we will try to display “Welcome” in a web browser.

First create a Node.js file as Myfirst.js and include the following code in a file:

var http = require('http');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/html'});
  res.end('Welcome');
}).listen(8080);

Now save the file on your machine: C:Users/Your/Name/myfirst.js

This code commands the computer to display “Welcome”, if anyone uses your computer on port 8080.

Command Line Interface:

• Node.js file needs to be executed in the “Command Line Interface” (CLI) program of your computer.
• Executing the program in command line interface depends on the operating system.  For windows users, the program needs to be implemented in the command prompt.

By navigating the folder to the path where the file “myfirst.js" is situated, the CLI should looks something like this:

C:Users/Your Name>_

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Initiate the Node.js File:

• The created file must be initiated by Node.js before some action can take place.
• Start your CLI, give input as node myfirst.js and hit enter:
• C:Users/Your Name>node myfirst.js
• Now, the computer will work as a server. Now, if anyone tries to access the system on port 8080, the user will be displayed the “Welcome” message in return. 
• Now, to see the output, you need to open the browser and type the following address: http://localhost:8080.

What is a module in Node.js?

• Modules are similar to libraries in JavaScript; they are a set of functions which you can include in your application.
• To include a module, you need to make use of require() function with the name of a module.
• var http = require('http');
• By doing this operation, you will now have access to http module, and is able to create a server.
• Built-in Node.js Modules
• Node.js has many built-in modules which can be used without any further installation process.

Here is a list of built-in Node.js modules:

Module	Description
assert	Provides a set of assertion tests
buffer	To handle binary data
crypto	To handle OpenSSL cryptographic functions
child_process	To run a child process
cluster	To split a single Node process into multiple processes
dns	To do DNS lookups and name resolution functions
dgram	Provides an implementation of UDP datagram sockets
events	To handle events
domain	Deprecated. To handle unhandled errors
fs	To handle the file system
os	Provides information about the operation system
path	To handle file paths
punycode	Deprecated. A character encoding scheme
querystring	To handle URL query strings
readline	To implement TLS and SSL protocols
tls	Provides classes used by a text terminal
tty	To access utility functions
util	To parse URL strings
url	To make Node.js act as an HTTP server
https	To make Node.js act as an HTTPS server
net	To create servers and clients
v8	To access information about V8 (the JavaScript engine)
vm	To compile JavaScript code in a virtual machine
zlib	To compress or decompress files
stream	To handle streaming data
timers	To execute a function after a given number of milliseconds
String decoders	To decode buffer objects into strings

Advantages of Node.js

• Node.js is not the typical programming language, instead it is a runtime environment, and is simple to learn for both frontend and backend developers.
• Back-end programmers who run node.js are likely to benefit from its high speed, efficiency, and high performance.
• Programmers using node.js have the freedom to select the best design patterns, architectures, modules, and features as they don’t have strict conventionsz

Disadvantages of Node.js 

• Its disadvantages include lack of consistency, depending on the API changes that frequently happen and that are often not compatible for back-end users.
• Developers regularly face problems with node.js applications as they become unresponsive while processing huge files.
• The node.js environment is built in a single-threaded format which reduces the efficient handling of applications of CPU like editing audio, graphics, and video files.  
• The node.js ecosystem having several of its tools appear to be unsupervised and the modules seem to be immature as they are incorrectly documented.

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Prerequisites to learn Node.js

To learn node.js you need to be proficient in understanding the concepts of JavaScript as few topics will include the development of web-based applications using node.js.

Average Salary

The average salary for a Javascript Developer in January 2018 was £62,500 and by the end of the year 2018, it rose by 9% (£6,888), according to CW Jobs. Here is the survey report of Node.js which states the development focus, overall presence, and the companies using Node.js.

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Future scope of Node.js

JavaScript is flourishing in the current IT job market, though many aspiring software developers think that landing a job in this field may put them into trouble. This is because the other languages dominate particular areas of the market, like a python in the case of data analytics.

There were plenty of jobs available for Java in 2017, and this is not the case now. The number of jobs for Specialists in Python and JavaScript are either going up or steadily increasing. Node.js is listed often as the valuable framework to get skilled, even for those people who choose to focus on the client side.

Referring to job listing sites may give you a negative understanding of the demand for Node.js developers. Many companies demand other skills like python and javascript for those who are getting hired for java or sql. Today, Node.js ranks pretty high among the best paying development jobs in IT.

Online Resources to Learn Node.js

Courses

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Books

Beginning Web Development with Node.js

The Node Beginner Book

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