is simply static collection, so immutable:
```
var all = document.querySelectorAll("*");
var length = all.length;
all[length] = 'whatever';
alert(all.length === length);
[].push.call(all, 'whatever');
alert(all.length === length);
```
you can put properties because is extensible but you won't change the index
nature of that collection neither you can change addressed variables ...
NodeList instances are created like this:
```
function Ecw(value) {
return {
enumerable: true,
writable: false,
configurable: false,
value: value
};
}
Object.defineProperties(
Object.create(NodeList.prototype),
{
"0": Ecw(document.documentElement),
"1": Ecw(document.head),
"2": Ecw(document.body),
"length": Ecw(3)
}
);
```
this one regardless the returned descriptor info (at least in Chrome) which
is not trustable with hosted natives
regards
On Wed, May 22, 2013 at 10:21 AM, Domenic Denicola <
dome...@domenicdenicola.com> wrote:
> From: Tab Atkins Jr. [jackalm...@gmail.com]
>
> > NodeList is an interesting case, actually. It's an Array, but with a
> type restriction.
>
> What do you mean by that? Surely you don't mean "can only store nodes":
>
> ```
> > var nodeList = document.querySelectorAll("div");
> undefined
>
> > nodeList.length
> 22
>
> > nodeList[22] = "not a node";
> "not a node"
>
> > nodeList[22]
> "not a node"
> ```
>
> On the other hand, not sure what's going on here:
>
> ```
> > nodeList[1] = "not a node either";
> "not a node either"
>
> > nodeList[1]
> <div class="banner">…</div>
>
> > Object.getOwnPropertyDescriptor(nodeList, "1")
> Object {value: div.banner, writable: true, enumerable: true, configurable:
> true}
> ```
>
> (both results in Chrome 27. Firefox 21 has a different pathology... It
> returns `undefined` for `nodeList[22]`, although
> `Object.isExtensible(nodeList) === true`. But it gets the second case
> right, giving `writable: false` to correctly reflect the behavior there.)
> _______________________________________________
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
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