获取 JavaScript 对象的所有键
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Get all keys of a JavaScript object
提问by tishma
I was wondering if there was a quick way to extract keys of associative array into an array, or comma-separated list using JavaScript (jQuery is ok).
我想知道是否有一种快速的方法可以使用 JavaScript（jQuery 可以）将关联数组的键提取到数组或逗号分隔列表中。
options = {key1: "value1", key2: "value2"};
Result should be the array:
结果应该是数组：
["key1", "key2"]
or just a string:
或者只是一个字符串：
"key1, key2"
回答by Nick Craver
You can easily get an array of them via a forloop, for example:
您可以通过for循环轻松获取它们的数组，例如：
var keys = [];
for(var key in options) {
if(options.hasOwnProperty(key)) { //to be safe
keys.push(key);
}
}
Then use keyshow you want, for example:
然后使用keys您想要的方式，例如：
var keyString = keys.join(", ");
You can test it out here. The .hasOwnProperty()check is to be safe, in case anyone messed with the object prototype and such.
你可以在这里测试一下。该.hasOwnProperty()检查是为了安全起见，在与物体原型和这种混乱的情况下任何人。
回答by pwl
options = {key1: "value1", key2: "value2"};
keys = Object.keys(options);
回答by Ege ?zcan
A jQuery way of doing it:
一种 jQuery 方法：
var keys = [];
options = {key1: "value1", key2: "value2"};
$.each(options, function(key, value) { keys.push(key) })
console.log(keys)
回答by Andy E
Most of the major browsers have this functionality built-in now, the method is Object.keys():
现在大多数主流浏览器都内置了这个功能，方法是Object.keys()：
var keys = Object.keys(options);
//-> ["key1", "key2"]
You can also use a little snippet to implement this in browsers that don't support it:
您还可以使用一个小片段在不支持它的浏览器中实现它：
Object.keys = Object.keys || (function () {
var hasOwnProperty = Object.prototype.hasOwnProperty;
return function (o) {
if (typeof o != "object" && typeof o != "function" || o === null)
throw new TypeError("Object.keys called on a non-object");
var result = [];
for (var name in o) {
if (hasOwnProperty.call(o, name))
result.push(name);
}
return result;
};
})();
That snippet works much the same as the one in Nick Craver's example with 2 exceptions:
该代码段与 Nick Craver 示例中的代码段非常相似，但有两个例外：
- It will throw a meaningful TypeError if you pass anything other than an Object in (or "associative array", if you like).
- It will work around an annoying DOM-related issue in Internet Explorer where collections don't have the
hasOwnPropertymethod.
- 如果您传入除 Object 之外的任何内容（或“关联数组”，如果您愿意），它会抛出一个有意义的 TypeError。
- 它将解决 Internet Explorer 中令人讨厌的 DOM 相关问题，其中集合没有该
hasOwnProperty方法。
This (and the other answers here) doesn't work around an IE enumeration bug, however. You can find more information and a partial work around for that on this answer here.
回答by Ege ?zcan
You can now use
您现在可以使用
Object.keys(obj)
to get an array consisting of the available keys in an object. Mozilla has usage and availability information.
获取由对象中的可用键组成的数组。Mozilla 有使用和可用性信息。
回答by Pointy
You can use $.each()in jQuery:
您可以$.each()在 jQuery 中使用：
function keyArray(obj) {
var rv = [];
$.each(options, function(key) { rv.push(key); });
return rv;
}
then
然后
var keys = keyArray(options);
gives you ["key1", "key2"]as an array, which you could jointo get a string.
给你["key1", "key2"]一个数组，你可以join得到一个字符串。
