javascript函数是对象吗？ [英] javascript functions are objects?

问题描述

一段时间以来，我一直在努力解决Javascript问题，并且无法在网络上找到解释。我想这是因为我没有输入正确的关键字，这也可能与我为什么挣扎在一起。

我的基本假设是，有可能改变对象：

 > var x = {'n'：2}; 
> x ['n'] 
 2 
> x ['n'] = 3; 
 3 
  

有效的工作。但仍然（函数也是对象）：

 > var addn = function（a）{
 var n = 2; 
 return n + a; 
} 
 
> ADDN（3）; 
 5 
> addn ['n'] = 3; 
 3 
> ADDN（3）; 
 5 
  

这次我无法改变'n'。有没有办法解决这个问题，同时保持功能的味道？而不是完全OO。我有一个相关的问题，就是如何维护函数的依赖关系，以便进行测试 - 再次不用OO？因为我正在寻找一个解决方案，但如果可能的话，我还想了解Javascript中的哪个机制让我挣扎。

干杯，

Mark

免责声明：
提到面向对象，我不打算对面向对象说任何话。而且我也不打算对VI或Emacs发表任何言论。如果我不知何故伤害了你的感情，请跳过这一段。

匿名函数并通过它访问函数对象的属性：

pre $ var c addn = function func（a）{
return func .n + a;
};

addn ['n'] = 3;
addn（3）; //返回6

I am struggling with a Javascript question for some time now and I was not able to find an explanation on the web. I guess it is because I do not enter the right keywords which might also be related to why I am struggling with this at all.

My basic assumption is that it is possible to alter objects:

> var x = {'n': 2};
> x['n']
2
> x['n'] = 3;
3

pheww that worked. But still (functions are objects, too):

> var addn = function(a) {
    var n = 2;
    return n + a;
}

> addn(3);
5
> addn['n'] = 3;
3
> addn(3);
5

This time I was not able to change 'n'. Is there a way to fix this while keeping the functional flavor? As opposed to going fully OO. A related question I have would be how to maintain dependencies of functions for the purpose of for example testing - again w/o going OO? Of cause I am looking for a solution but if possible I would also like to understand which mechanism in Javascript makes me struggling.

Cheers,

Mark

Disclaimer: By mentioning OO I do not intent to say anything against OO. And I do not intent to say anything against VI or Emacs either. If I somehow hurt your feelings please skip this one.

解决方案

If I understand your question correctly, you can give a name to your anonymous function and access the function object's properties through that:

var addn = function func(a) {
  return func.n + a;
};

addn['n'] = 3;
addn(3); // returns 6

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