是否可以在同一对象内引用对象? [英] Is it possible to reference object within the same object?

问题描述

我一直在纠缠jQuery插件代码，并且试图将所有公共变量放入单个对象中以便于访问.我在下面提供了一些有关如何执行此操作的示例，但我想知道其他人如何处理此问题.

I've been messing around with jQuery plugin code and I'm trying to put all of my common variables into a single object for easy access. I have included a few examples below on how I've done this, but I'm wondering how others deal with this problem.

让我说我有这个

var x = function(options){
 var defaults = {
  ulist   : $('ul#list'),
  listLen : $('ul#list').children().length
 }
 $.extend(options, defaults);
 // do other stuff
}

我想做的是使用ulist对象作为基础，然后找到li的数量

What I'm trying to do is use the ulist object in as a base, then find the number of li's

我想我可以做到:

var x = function(options){
 var defaults = {
  ulist   : $('ul#list'),
  listLen : 0
 }
 defaults.listLen = defaults.ulist.children().length;
 $.extend(options, defaults);
 // do other stuff
}

或者这个:

var x = function(options){
 var defaults = {
  ulist : $('ul#list')
 };
 var defaults2 = {
  listLen : defaults.ulist.children().length
 }
 $.extend(defaults, defaults2);
 $.extend(options, defaults);
 // do other stuff
}

以上代码示例只是一起使用，仅是为了使您理解该想法.无论如何，还有更好的方法吗?

The above code samples are just thrown together, and only meant to get the idea across to you. Anyway, is there a better way to do this?

推荐答案

我会说您发布的此版本，但无需将listLen初始化为0.

I would say this version that you posted, but no need to initialize listLen to 0.

var x = function(options){
 var defaults = {
  ulist   : $('ul#list'),
  listLen : 0    // Remove this line
 }
 defaults.listLen = defaults.ulist.children().length;
 $.extend(options, defaults);
 // do other stuff
}

---

您的第二个解决方案也可以使用，但是不需要对$.extend()进行两次调用.它可以接受多个对象.

Your second solution would work too, but no need to do two calls to $.extend(). It can accept more than one object.

$.extend(options, defaults, defaults2);

您的第一个解决方案似乎仍然更好.

Your first solution still seems better.

(如前所述，您可以使用一个函数.尽管我仍然在defaults对象的初始化之外分配该函数，所以您可以在最后添加函数调用运算符()并对其进行调用就像财产一样.

(As pointed to, you can use a function. Although I'd still assign the function outside the initialization of the defaults object, so you can add the function call operator () at the end, and call it like a property.

var x = function(options){
    var defaults = {
        ulist: $('ul#list')
    } 

    defaults.listLen = function() {return defaults.ulist.children().length}();
}

现在，您可以像访问属性一样访问defaults.listLen并获取函数调用的结果，就像在jQuery对象上调用.length一样.

Now you can access defaults.listLen like a property and get the result of the function call, sort of like calling .length on a jQuery object.

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