在JavaScript文字中使用变量作为属性名称？ [英] Use variable for property name in JavaScript literal?

问题描述

我是JavaScript的新手，并尝试对其进行一些实验。我有一个问题。我知道我们可以在运行时在Javascript对象中创建新属性，但是也可以为该属性分配值。例如。

I am new to JavaScript and trying to do some experiment with it. I have one question. I know we can create new properties in Javascript objects during runtime but would that property can be assigned a value too. For example.

var value = "New value";

var table = new Object();

var newValue = table[value];

现在，我知道值表有一个名为value的新属性。但是这个值键包含的信息是新值。那么，这是否意味着现在表格对象如下：

Now, I know that value table has a new property called "value". but does that "value key contains the information as " New Value". So, does that mean now table object is like following:

table = {
value:"New Value";
}

Thanks提前为你提供帮助。

Thanks for your help in advance guys.

-Vik

推荐答案

你'分配访问令人困惑。

You're confusing accessing with assigning.

// Assigns a variable named 'value' with a value of 'New Value'.
var value = "New value";
// Creates a variable named 'table' as a blank Object.
var table = new Object(); // Alternatively - table = {};
// Attempts to access "New Value" from object "table" which returns undefined.
var newValue = table[value];

如果要为对象指定属性，请执行以下操作：

If you want to assign properties to an object you do so like this:

// Assumes table is still an object.
table['key'] = 'value';

// Note that I almost _always_ opt for the variable['key'] notation over
// the variable.key notation because it allows you to use keys
// that would otherwise not be valid as identifiers.
table['Some Key'] = 'Some Value'; // This works.
table.Some Key = 'Some Value'; // This does not.

稍后，当你想要检索该值并将其存储在一个新变量中时，那就是你做的时候这个：

Later, when you want to retrieve that value and store it in a new variable, that's when you do this:

var newVariable = table['key'];

希望澄清一些。如果我可以扩展它的任何部分，请告诉我。

Hopefully that clarifies some. Please let me know if I can expand on any part of it.

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