Is node free?

node is free; node was released in May 2009 and developed by Ryan Dahl. It is a JavaScript running environment based on the Chrome V8 engine. It uses an event-driven, non-blocking I/O model, allowing JavaScript runs on the server-side development platform; Node uses Module modules to divide different functions to simplify application development.

The operating environment of this tutorial: Windows 10 system, Node.js version 17, DELL G3 computer

Is node free?

is free.

Introduction to Node.js

• Node.js is an open source server environment

• Node. js is free

• Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)

• Node .js uses JavaScript on the server

Node.js was released in May 2009 and was developed by Ryan Dahl. It is a JavaScript running environment based on the Chrome V8 engine and uses an event driver. , non-blocking I/O model, allowing JavaScript to run on the server-side development platform, which makes JavaScript a scripting language on par with server-side languages ​​such as PHP, Python, Perl, and Ruby.

Node.js optimizes some special use cases and provides alternative APIs to make V8 run better in non-browser environments. The V8 engine executes Javascript very quickly and has very good performance. It is based on Chrome JavaScript The platform established at runtime is used to easily build network applications with fast response speed and easy expansion.

Development History

In February 2009, Ryan Dahl announced on his blog that he was preparing to create a lightweight web server based on V8 and provide a set of libraries.

In May 2009, Ryan Dahl released part of the initial version of the Node package on GitHub. In the following months, some people began to use Node to develop applications.

Node.js lectures were arranged at both JSConf conferences in November 2009 and April 2010.

At the end of 2010, Node received funding from cloud computing service provider Joyent, and founder Ryan Dahl joined Joyent to be responsible for the development of Node full-time.

In July 2011, Node released the Windows version with the support of Microsoft.

In 2016, the leftpad incident led to the birth of Yarn

In 2021, the latest version Node.js 17 will be released.

Function module

Node uses the Module module to divide different functions to simplify application development. Modules modules are a bit like class libraries in C language. Each Node class library contains a very rich variety of functions. For example, the http module contains many functions related to the http function, which can help developers easily operate on http, tcp/udp, etc., and can also Easily create http and tcp/udp servers.

It is very convenient to use modules in the program. You only need to do the following:

Here, the http class library is introduced, and the reference to the http class library is stored in the http variable. At this time, Node will search for the node_modules directory in our application and search for the http module in this directory. If Node.js cannot find this directory, it will search in the global module cache. Users can specify the location of the module through relative or absolute paths, for example:

var myModule = require('./myModule.js');

The module contains many functional code snippets , most of the code in the module is private, which means that the function methods and variables defined in the module can only be called in the same module. Of course, some methods and variables can be exposed outside the module. In this case, the exports object can be used to achieve this.

Recommended learning: "node.js Video Tutorial"

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