JS原型与继承操作示例

<script>var Beverage = function(){};Beverage.prototype.boilWater = function(){  console.log("把水煮沸");};Beverage.prototype.brew = function(){  throw new Error("子类必须重写该方法");};Beverage.prototype.pourInCup = function(){  throw new Error("子类必须重写该方法");};Beverage.prototype.addCondiments = function(){  throw new Error("子类必须重写该方法");};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();//继承父类BeverageCoffee.prototype.boilWater = function(){  console.log("把水煮沸");};Coffee.prototype.brew = function(){  console.log("用沸水冲泡咖啡");};Coffee.prototype.pourInCup = function(){  console.log("把咖啡倒进杯子");};Coffee.prototype.addCondiments = function(){  console.log("加糖和牛奶");};var Tea = function(){};Tea.prototype = new Beverage();//继承父类BeverageTea.prototype.boilWater = function(){  console.log("把水煮沸");};Tea.prototype.brew = function(){  console.log("用沸水浸泡茶叶");};Tea.prototype.pourInCup = function(){  console.log("把茶水倒进杯子");};Tea.prototype.addCondiments = function(){  console.log("加入柠檬");};Tea.prototype.customerWantsCondiments = function(){  return window.confirm("请问需要加调料吗?");};var coffee = new Coffee();//实例化Coffeecoffee.init();var tea = new Tea();//实例化Teatea.init();</script>