创建对jQuery.data键的本地引用 [英] Creating a local reference to a jQuery.data key

问题描述

我正在对jQuery.data()进行一些测试，并且试图创建对某个数据键的本地引用，我希望可以对该数据键进行本地更改，并且仍然会影响外部".我想举个例子会更好，因为我将半长代码发布在jsFiddle而不是这里:

I'm doing some testing on jQuery.data(), and I'm trying to create a local reference to a certain data-key, which I hopefully can change locally and still affect "outside". I think it would be better with an example, due to the semi-long code I posted it on jsFiddle instead of here:

http://jsfiddle.net/esbenp/p4kt2/22/

我希望的输出是:

{1: {length: 1}, total: 1}

但局部变量仅会影响length属性:

but only the length property is affected by incrementing the local variable:

{1: {length: 1}, total: 0}

我该怎么办?

推荐答案

如果将对象(或数组)存储在.data()中，则实际上是在存储引用，如果您这样做:

If you store an object (or array) in .data() then you're actually storing a reference to it, so if you do:

var obj = { key: 'value' }
$(el).data('obj') = obj;
obj.key = 'new value';

$(el).data('obj').key也将是new value，因为它是同一对象.

但是，如果存储的值不是普通类型(例如数字或字符串)，则会存储其副本:

However if the value stored is a plain type instead (e.g. a number or a string) that a copy of it will be stored:

var n = 5;
$(el).data('obj') = n;
n++;

$(el).data('obj')仍为5.

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