JavaScript：模块模式差异 [英] JavaScript: module pattern differences

问题描述

var module = (function(){
    return {} 
})()

和

(function(context){
    var module = {}
    context.module = module;
})(this)

推荐答案

不等于变量。在全局范围（即这个引用窗口中），它们是类似的。然而，例如，当您尝试 删除 他们：

A property of this is not equivalent to a variable. In the global scope (i.e. where this references window), they are similiar. Yet, for example they will have a different behavior when you try to delete them:

> this.module = {};
> delete this.module
true
> var module = {};
// cant be deleted

除此之外，两个代码片段都创建一个空对象，在一个闭包中，您可以定义本地（私有）变量/函数等。在第二个函数中，对象也被分配给局部变量 module ，但可以在第一个。

Apart from that, both snippets create an empty object, wrapped inside a closure where you could define local (private) variables/functions etc. In your second function the object is also assigned to the local variable module, but that could be done in the first one as well.

@Eric：您的方法，使用 new operator ，第一个关于变量。但是，它将创建一个匿名函数的实例，而不是返回一个普通对象。它将继承自定义原型的属性，所以例如 module.constructor 然后将指向匿名函数（不能被垃圾回收，但是甚至重用以创建一个克隆）。我不建议使用这个。

@Eric: Your approach, using the new operator, is similiar to the first one regarding the variable. However, it will create an instance of that anonymous function instead of returning a plain object. It will inherit properties from a custom prototype, so for example module.constructor will then point to the anonymous function (which cannot be garbage collected, but e.g. even reused to create a clone). I would not recommend to use this.

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