列出窗口对象的所有属性？ [英] List all properties of window object?
问题描述
我希望（动态）获取浏览器当前知道的HTML元素列表，例如 HTMLPreElement ， HTMLSpanElement 等。这些对象是全局的，即
I'm looking to (dynamically) obtain a list of HTML elements the browser is currently aware of, such as HTMLPreElement, HTMLSpanElement etc. These objects are global, i.e.
console.log('HTMLPreElement' in window); //=> true
所以我认为我可以使用 getOwnPropertyNames 像这样：
So I thought I'd be able to use getOwnPropertyNames like this:
console.log(Object.getOwnPropertyNames(window));
获取全局属性的完整列表（MDN声明它返回可枚举和不可枚举的属性）。
to obtain the full list of global properties (MDN states that this returns both enumerable and non-enumerable properties).
使用上面的内容，我得到一个包含大约70个属性区域的数组。但是，它不包括像 HTMLPreElement 这样的对象 - 只有 HTMLElement 。我也尝试过：
Using the above, I get an array with around 70 property nanes. But, it doesn't include objects like HTMLPreElement - only HTMLElement. I also tried:
console.log(Object.getOwnPropertyNames(window.Window.prototype));
带回更大的清单（包括 addEventListener 等）但是再一次，没有 HTMLPreElement 。
which brings back a bigger list (including addEventListener etc) but again, no HTMLPreElement.
那么，这些什么地方 HTML {Tag}元素对象驻留？
So, where the heck do these HTML{Tag}Element objects reside?
推荐答案
在Firefox中，除非明确要求作为全局变量，否则不会添加其全局对象的元素行为或财产。也许Firefox懒惰地将它们加载到环境中，这样它们就不会消耗内存，除非实际需要它们。
In Firefox, it seems to be the behavior of elements that their global object is not added unless explicitly requested as a global variable or property. Perhaps Firefox lazy loads them into the environment so that they don't consume memory unless they're actually needed.
当通过 Object.getOwnPropertyNames <只是简单地请求全局对象的键时，它们似乎不显示em>除非它们首先被如上所述明确引用。
It seems that they do not show up when simply requesting the keys of the global object via Object.getOwnPropertyNames unless they've first been explicitly referenced as described above.
这篇关于列出窗口对象的所有属性？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
