The principle and use of nodejs

This article mainly explains the principle and use of nodejs. Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let Xiaobian take you to learn "the principle and use of nodejs"!

Node.js is a server-side JavaScript runtime environment based on Chrome V8 engine and event-driven I/O.

creation server

Node provides http module, http module is mainly used to build HTTP server and client

const http = require('http');const server = http.createServer((req,res)=>{ res.writeHead(200, { 'Content-Type': 'text/plain' }); res.end('Hello world');})server.listen(3000)

file system

The fs module provides an API for interacting with file systems in a manner that mimics standard POSIX functions. All file system operations have synchronous and asynchronous forms. Asynchronous forms always take completion callbacks as their last argument. The parameters passed to the completion callback depend on the method, but the first parameter is always reserved for exceptions.

const fs = require('fs');//read fs.open('myfile','r',(err,data)=>{ if(err){ return console.error(err) } readMyData(data);})//write fs.open('myfile','wx',(err,data)=>{ if(err){ return console.error(err) } writeMyData(data);}) At this point, I believe that everyone has a deeper understanding of the "principle and use of nodejs". Let's actually operate it! Here is the website, more related content can enter the relevant channels for inquiry, pay attention to us, continue to learn!