观察者模式

事件驱动模型，观察者模式

同一个事件，多个监听器

const EventEmitter = require("events");

const myEmitter = new EventEmitter();

// 这里是两个观察者，观察对应的对象，等待对象做出动作
myEmitter.on("newSale", () => {
  console.log("There was a new sale");
});

myEmitter.on("newSale", () => {
  console.log("Custumer name: Kihyun");
});

// 这是事件发出的对象
myEmitter.emit("newSale");

一个http请求的例子，监听到请求事件会console.log

const http = require("http");

const server = http.createServer();

server.on("request", (req, res) => {
  console.log("Request received!");
  console.log(req.url);
  res.end("Request received!");
});

server.on("request", (req, res) => {
  console.log("Another request 
标签：myEmitter,http,log,观察者,模式,server,console,const	

来源： https://www.cnblogs.com/kihyunBlog/p/16387553.html