利用空对象实现继承

funcition Animal () {
}
Animal.prototype.type = "Animal"
function Cat (name,color) {
  this.name = name;
  this.color = color;
}
var f = function () { }
f.prototype = Animal.prototype
Cat.prototype = new f()
Cat.protope.constructor = Cat
复制代码

• 封装成方法
  

function extend(child,parent){
  var f = function () {}
  f.prototype = parent.prototype
  child.prototype = new f()
  child.prototype.constructor = child
  child.uber = parent.prototype
}
复制代码

• 使用
  

entend(Cat,Animal)
var cat1 = new Cat("大白","Black")
alert(cat1.type) // 输出Animal
复制代码

这个extnd函数也是YUI库实现继承的方法

原文：http://www.ruanyifeng.com/blog/2010/05/object-oriented_javascript_inheritance.html

转载于:https://juejin.im/post/59faa4f2f265da430d57587a