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This article focuses on "which modules are made up of Node.js runtime". Interested friends may wish to take a look at it. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "which modules are made up of Node.js runtime"?

Nodejs is a platform based on Chrome JavaScript runtime. It is a development platform that allows JavaScript to run on the server. It is mainly used to build network applications with fast response and easy to expand.

This tutorial operating environment: windows7 system, nodejs version 12.19.0, DELL G3 computer.

Node.js is a platform based on Chrome JavaScript runtime and a development platform for JavaScript to run on the server side. It makes JavaScript a scripting language on a par with server-side languages such as PHP, Python, Perl, Ruby and so on.

Node.js is an event-driven JavaScript environment on the server side of Google. The V8 engine based on Google executes Javascript very fast and the performance is very good.

Node.js is used to easily build network applications with fast response and easy to expand.

What is the runtime?

The so-called runtime is a series of components or tools that the program depends on while it is running; when these tools and components are packaged and provided to the programmer, the programmer can run the code he has written.

For JavaScript, it relies on the following components at run time:

1) interpreter

JavaScript is a scripting language that needs to run while interpreting and compiling which source code is used. The whole process is completed by the interpreter. Without an interpreter, JavaScript is just a bunch of plain text files that cannot be recognized by a computer.

2) Standard library

We will call some built-in functions in the JavaScript code, which are not written by us, but are included in the standard library.

3) Local module

The so-called local modules are modules that have been compiled in advance. They are binary files that are no different from executable files in their internal structure, but cannot be run alone. These native modules are actually dynamic link libraries (.dll files in Windows), and if you have used compiled languages such as C or C++, you should be able to understand it better.

Many features of JavaScript need to be supported by local modules, such as:

Cookie is used to store a small amount of user data. It is a small file on the user's computer. The use of Cookie must be supported by the file operation module.

Ajax can request data from the server with the help of the Internet, which is a network operation and must be supported by the network library.

Tracking the execution of the code step by step to find logic errors is called debugging and requires the support of a Debugger.

JavaScript can manipulate HTML, which requires the HTML parsing module to build the DOM tree ahead of time.

Local modules generally encapsulate general functions and require high performance, so they are usually implemented in compiled languages, such as C language, C++, assembly language and so on.

The JavaScript interpreter needs the support of the local module, and the standard library will call the interface of the local module when writing, and the JavaScript code we write will not use the local module directly, so the Web front-end programmer can't touch them.

The local module is the hero behind the scenes, it is inconspicuous, but indispensable.

Summary

Interpreters, standard libraries, native modules and other components / tools work together to support the operation of JavaScript code, which are collectively referred to as the JavaScript runtime.

Before Node.js, the JavaScript runtime was bundled in the browser and appeared as various modules of the browser. This means that in order to run JavaScript code, you must start the browser, JavaScript can not escape the palm of the browser, its functionality is greatly limited and can only be used as a web script.

The composition of Node.js

Node.js runtime is mainly composed of V8 engine, standard library and local modules, especially the number of local modules, which determines the strength of Node.js functions from the bottom.

1) V8 engine

The V8 engine is the JavaScript interpreter, which parses and executes JavaScript code.

V8 engine draws lessons from many technologies of Java virtual machine and C++ compiler, it compiles JavaScript code directly into native machine code, and uses caching mechanism to improve performance, which makes JavaScript run as fast as binary programs.

2) Local module

Node.js integrates a number of high-performance open source libraries, which are implemented in the C _ Candle + language, such as:

The module describes libuv, a cross-platform, event-driven, asynchronous Imax O library. However, libuv is not limited to Imax O, it also provides other functions such as process management, thread pool, signal processing, timer and so on.

In Linux, everything is a file, and the Icano here includes not only file reading and writing, but also database reading and writing, network communication (socket) and so on. NmpNode.js package manager, you can download packages, install packages, uninstall packages, update packages, upload packages, etc. Http_parser is a lightweight HTTP parser written in C language to support Web application development. Zlib industrial-grade data compression / decompression module, Nodejs uses zlib to create synchronous, asynchronous or streaming compression / decompression interface. OpenSSL this module provides many closely tested encryption / decryption functions that modern Web relies on for security, such as SSL protocol and https protocol. C-ares asynchronous DNS query and parsing libraries.

Node.js runs JavaScript code directly on the computer and gives JavaScript powerful capabilities, so its native module is quite different from the runtime in the browser, if not relevant. Node.js abandoned browsers almost completely and built a whole new set of JavaScript runtimes from scratch.

3) Standard library

The native module is written in JavaScript Cash +, while Node.js is intended for JavaScript developers, so it is necessary to encapsulate the native module's Cmax Cure + interface, provide an elegant set of JavaScript interfaces to developers, and keep the interface consistent on different platforms (operating systems).

This set of JavaScript interfaces is the Node.js standard library. Whether the standard library is elegant and powerful determines the ease of use of Node.js and directly affects the market performance of Node.js.

At this point, I believe you have a deeper understanding of "which modules are made up of the Node.js runtime". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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