<script>var Beverage = function(){};Beverage.prototype.boilWater = function(){  console.log("把水煮沸");};Beverage.prototype.brew = function(){  throw new Error("子類必須重寫該方法");};Beverage.prototype.pourInCup = function(){  throw new Error("子類必須重寫該方法");};Beverage.prototype.addCondiments = function(){  throw new Error("子類必須重寫該方法");};Beverage.prototype.customerWantsCondiments = function(){  return true;};Beverage.prototype.init = function(){  this.boilWater();  this.brew();  this.pourInCup();  if(this.customerWantsCondiments){    this.addCondiments();  }};var Coffee = function(){};Coffee.prototype = new Beverage();//繼承父類BeverageCoffee.prototype.boilWater = function(){  console.log("把水煮沸");};Coffee.prototype.brew = function(){  console.log("用沸水沖泡咖啡");};Coffee.prototype.pourInCup = function(){  console.log("把咖啡倒進杯子");};Coffee.prototype.addCondiments = function(){  console.log("加糖和牛奶");};var Tea = function(){};Tea.prototype = new Beverage();//繼承父類BeverageTea.prototype.boilWater = function(){  console.log("把水煮沸");};Tea.prototype.brew = function(){  console.log("用沸水浸泡茶葉");};Tea.prototype.pourInCup = function(){  console.log("把茶水倒進杯子");};Tea.prototype.addCondiments = function(){  console.log("加入檸檬");};Tea.prototype.customerWantsCondiments = function(){  return window.confirm("請問需要加調料嗎?");};var coffee = new Coffee();//實例化Coffeecoffee.init();var tea = new Tea();//實例化Teatea.init();</script>