Javascript 如何在散列中将变量值分配为变量名？
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how to assign variable value as variable name in a hash?
提问by mikkelbreum
I need to define a hash for posting some ajax data using jQuery. The hash will look something like:
我需要定义一个散列来使用 jQuery 发布一些 ajax 数据。哈希将类似于：
var setname = 'set_1';
elements = { set_1: {'beer','water','wine'} };
The challenge I need to solve is 'set-1' (the key of Array elements) should be dynamically named based on the value of var setname.
我需要解决的挑战是 'set-1'（数组元素的键）应该根据var setname.
I want to avoid using eval()of course..
in PHP it can be done using the double dollar sign like this: $$setname, but what's the way to do this in JavaScript?
我eval()当然想避免使用.. 在 PHP 中它可以使用像这样的双美元符号来完成：$$setname，但是在 JavaScript 中这样做的方法是什么？
回答by Daniel Vandersluis
You can do what you'd like to like so:
你可以做你想做的事：
var setname = 'set_1', elements = {};
elements[setname] = ['beer','water','wine'];
alert(elements['set_1']); // beer,water,wine
See this in action at http://jsfiddle.net/x5KRD/.
在http://jsfiddle.net/x5KRD/ 上查看此操作。
All objects in JS can be accessed using dot notation(obj.method()or obj.property), or bracket notation(obj['method']()or obj['property']). Using bracket notation lets you dynamically specify method/property/key names.
JS 中的所有对象都可以使用点符号（obj.method()或obj.property）或括号符号（obj['method']()或obj['property']）访问。使用括号表示法可以动态指定方法/属性/键名称。
For example, while clumsy, window['alert']('hi')is equivalent to window.alert('hi').
例如，虽然笨拙，但window['alert']('hi')相当于window.alert('hi').
Note that your code won't work as-is, anyways, because you're using object literal notation ({'beer','water','wine'}) to contain an array (it should be in square brackets ['beer','water','wine']instead). Object literals need to have key-value pairs.
请注意，无论如何，您的代码不会按原样工作，因为您使用对象文字符号 ( {'beer','water','wine'}) 来包含数组（它应该放在方括号中['beer','water','wine']）。对象字面量需要有键值对。
回答by kanaka
var setname = 'set_1',
elements = {};
elements[setname] = ['beer','water','wine'];
回答by Pointy
You have to understand that there's really no such thing as "JSON notation" in Javascript - it's native Javascript notation that we're talking about. What jQuery wants is a Javascript value for the POST data, not necessarily a Javascript object constant.
你必须明白在 Javascript 中真的没有“JSON 表示法”这样的东西——我们正在谈论的是原生 Javascript 表示法。jQuery 想要的是 POST 数据的 Javascript 值，不一定是 Javascript 对象常量。
Thus, your code will prepare your POST data like this:
因此，您的代码将像这样准备您的 POST 数据：
var elements = {};
elements[setName] = { /* something */ };
elements[somethingElse] = { /* something else */ };
and so on. When you're ready to do the POST, you'd just use "elements":
等等。当您准备好进行 POST 时，您只需使用“元素”：
$.post(url, elements, function() { /* callback code */ });
