利用CoffeeScript的`extends`与Backbone.js的`extend`之间的根本区别 [英] Fundamental differences between utilizing CoffeeScript `extends` vs. Backbone.js `extend`

问题描述

什么是使用之间的根本区别的CoffeeScript 扩展与Backbone.js的延长？

What are the fundamental differences between utilizing CoffeeScript extends vs. Backbone.js extend?

例如，如何为

class User extends Backbone.Model

从

User = Backbone.Model.extend()

推荐答案

两个旨在是等价的。引述Backbone.js的更新日志：

The two are intended to be equivalent. To quote the Backbone.js changelog:

0.3.0：主干课程可现在CoffeeScript的类无缝地继承

0.3.0: Backbone classes may now be seamlessly inherited by CoffeeScript classes.

这两个CoffeeScript中的儿童伸出父和骨干的儿童= Parent.extend（）做三个重要的事情：

Both CoffeeScript's Child extends Parent and Backbone's Child = Parent.extend() do three important things:

1. （最重要的）他们建立 Child.prototype 到新的ctor ，其中男星是一个函数，其原型是 Parent.prototype 。它建立原型继承。


2. 它们全部复制父的静态属性到儿童。


3. 他们建立儿童.__ super__ =父。这主要是为了支持CoffeeScript中的红宝石般的超级关键字儿童的方法。

1. (Most important) They set Child.prototype to new ctor, where ctor is a function whose prototype is Parent.prototype. That establishes prototypal inheritance.
2. They copy all of Parent's static properties onto Child.
3. They set Child.__super__ = Parent. This is mainly to support CoffeeScript's Ruby-like super keyword in Child's methods.

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