# Node.js

• node 的全局对象

# support

• officail learn
• 上手 Node.js

# Node core

• an open-source and cross-platform JavaScript runtime environment
• runs the V8 JavaScript engine
• A Node.js app runs in a single process, without creating a new thread for every request 单进程哈
• written using non-blocking paradigms
• provides a set of asynchronous I/O primitives in its standard library that prevent JavaScript code from blocking
• resume the operations when the response comes back

# 初探，搞个服务器

• new a file named app.js

const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;

// a request (an http.IncomingMessage object) 
// a response (an http.ServerResponse object).
const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World'); // actually is process.stdout.write('Hello World!\n')
});

server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

• run your web server using node app.js
• Visit http://localhost:3000
• you will see a message saying "Hello World".