javascriptInherit.js

var http = require("http")
// var util = require("util")
var EventEmitter = require("events").EventEmitter

//============ version 1 ==============

var Ticker = function () {
    setInterval(()=>{
        console.log("tick")
        this.emit("tick")
    }, 1000)
}

EventEmitter.call(Ticker.prototype)
Object.setPrototypeOf(Ticker.prototype, EventEmitter.prototype)
// util.inherits(Tick, EventEmitter) // 동일한 표현

var ticker = new Ticker()
ticker.on("tick", ()=>{
    console.log("tock")
})

//============ version 2 ==============

var ticker = Object.create(new EventEmitter())

setInterval(()=>{
    console.log("tick")
    ticker.emit("tick")
}, 1000)

ticker.on("tick", ()=>{
    console.log("tock")
})