使用下划线与主干延长（） [英] extend() using underscore vs. backbone

问题描述

我知道骨干在一定程度取决于下划线和jQuery。是否有下面的两条线之间的区别？

I know backbone is somewhat depending on underscore and jquery. Is there difference between the two lines below?

app.notifications = _.extend({}, Backbone.Events);

和

app.notifications  = Backbone.Events.extend({});

如果他们的不可以一样，有什么不同？

If they are NOT the same, how different?

推荐答案

Backbone.Events.extend不存在，
所以我将把Backbone.Model来代替。

Backbone.Events.extend does not exist, so I will refer to Backbone.Model instead.

_。扩展（目标，mixin1，mixin2）是要属性复制到目标对象

_.extend(target, mixin1, mixin2) is going to copy properties into the target object

Backbone.Model.extend将会子类 Backbone.Model基本上使一个构造函数（功能），其原型有您所提供的性能。这将允许你做出新的类的实例

Backbone.Model.extend is going to subclass Backbone.Model basically make a constructor (function) whose prototype has your provided properties. This will allow you to make instances of your new class

var Person = Backbone.Model.extend({name: 'yourName'});
var me = new Person();
alert(me.name);

，而 _。延长将失败

var Person = _.extend({name: 'yourName'}, Backbone.Model);
var me = new Person();  //error b/c Person is a regular object
alert(me.name);

在短期Backbone.Model.extend创建一个新构造（功能），而_.extend修改现有对象;

In short Backbone.Model.extend creates a new constructor (function), while _.extend modifies an existing object;

var modified = {};
alert(modified === _.extend(modified, Backbone.Model)); //true
alert(modified === Backbone.Model.extend(modified)); //false

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