对象中对象中的Javascript`this`? [英] Javascript `this` in objects-in-objects?

问题描述

抱歉，帖子标题模糊，我无法为这篇帖子用英文写出正确的名称.

Sorry for fuzzy post title, I can't formulate the correct name in English for this post.

例如我有这样一个对象:

For example I have such an object:

var APP = {
    a : 1,
    b : function(){
        return this.a;
    }
}

这样，如果我调用 console.log ( APP.b() ) 而 this 将引用 APP，结果将是 1.

In such way, if I call console.log ( APP.b() ) than this will be referring to APP and result will be 1.

但是如何从子对象连接到APP呢?示例:

But how to connect to APP from sub-object? Example:

var APP = {
    a : 1,
    b : function(){
        return this.a;
    },
    c : {
        c1: function(){
             return APP.a;
        }
    }
}

console.log ( APP.c.c1() ) // 1

此示例有效，但直接指向 APP 是个坏主意.例如:

This example works, but it's bad idea to point directly to APP. For example:

APP2 = APP;
APP = null;
console.log ( APP2.b() );  // 1
console.log ( APP2.c.c1() ); // APP is undefined

UPD:

我有一半的决定:如果我像方法一样声明属性 c:

I've got half-decision: if I declare property c like a method:

c : function(){
    var self = this;
    return {
        c1: function(){
            return self.b();
        },
        c2: function(){}
    }
}

它会工作，但我应该调用一个方法而不是属性(括号太多):

It will work, but I should call a method but not property (too much brackets) :

console.log( APP2.c().c1() ) 而不是 console.log( APP2.c.c1() )

推荐答案

您可以创建工厂方法:

var APP = (function(){
   var self;
   return self = {
      a : 1,
      b : function(){
          return this.a; // could be self, only differs in non-context use
      },
      c : {
          c1: function(){
               return self.a;
          }
      }
   };
})();

APP2 = APP;
APP = null;
APP2.b();  // 1
APP2.c.c1(); // 1

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