~~~ var eventEmitter = require('events') var myEmitter = new eventEmitter() //注册时间 myEmitter.on('begin', function () { console.log("begin") }) myEmitter.on('end', function () { console.log("end") }) //一共注册了多少个事件 console.log(myEmitter.eventNames()) //触发事件 myEmitter.emit('begin') ~~~ 输出 ``` [ 'begin', 'end' ] begin ```