What is Nodejs

1. What is nodejs

1. Node.js® is a JavaScript runtime built on Chrome’s V8 JavaScript engine.

   1. Not a language, library, framework

   2. Is a js runtime environment

   3. nodejs can parse and execute js code, compared to the previous only browser can parse and execute js code, now Js can run completely without the browser.

   4. The difference between js in the browser and js in nodejs

      1. The js in the browser is composed of three parts: ecmascript, DOM, and BOM

      ​ 2. js in nodejs has no BOM, DOM, only ecmascript

      3. And in the js execution environment of node, some APIs for server-level operations are provided for js
         1. File reading and writing (Js in the browser does not support)
         2. Network service construction
         3. Network communication
         4. HTTP server...

   5. Runtime environment built on Chrome's V8 engine

      1. Engine: Analyze and execute Js code
      2. Chrome's V8 engine is currently recognized as the fastest parsing and executing js code
      3. The author of Nodejs ported the V8 engine in Chrome and developed an independent js runtime environment (Nodejs).

   6. Node.js uses an event-driven,non-blocking I/O model that makes it lightweight and effcient

      1. event-driven event-driven
      2. non-blocking I/O model Non-blocking I/O model (asynchronous)
      3. lightweight and efficient

   7. Node.js’ package ecosystem,npm is the largest ecosystem of open source libraries in the world

      1. npm is the world's largest open source library ecosystem and is based on Nodejs
      2. Most js-related packages are stored on npm, in order to make it more convenient for developers to download and use packages

2. What can nodejs do

1. web server backend
2. Command line tool
   1. npm(node)
   2. hexo (node)
   3. git©
   4. …
3. The front-end contacts with node the most are the command line tools: webpack, npm, etc.

3. Resources

1. "Deep Move Out of Node.js"
   1. Author: Ling Park
   2. Partial theory, understanding the underlying principle is helpful
2. "Node.js authoritative guide" API explanation
3. javascript standard reference tutorial (alpha): https://javascript.ruanyifeng.com/
4. Getting started with Node: https://www.nodebeginner.org/index-zh-cn.html
5. Official API documentation: https://nodejs.org/dist/latest-v6.x/docs/api/
6. Chinese document (older version): http://www.nodeclass.com/api/node.html
7. CNODE community: https://cnodejs.org/
8. CNODE-Getting Started for Newbies: https://cnodejs.org/getstart