I see. Thank you.
On Wed, Jun 8, 2011 at 6:45 PM, Adam <[email protected]> wrote:
> Very much.
>
> Not all browsers expose the real prototype of an object, so you can't
> always navigate the chain. The prototype property of a function/
> constructor is exposed, but that only gets you one layer deep.
>
> when you create a function:
>
> var a = function() {};
>
> You also create a prototype object auto-magically:
>
> a.prototype;
>
> This prototype has a magic reference back to the function
>
> a.prototype.constructor === a;
>
> So that's what you're seeing. If you want to navigate the chain on an
> object, you need to use the __proto__ property:
>
> var b = new a();
> var c = b.__proto__;
> var d = c.__proto__;
> And so on until Object.prototype, and then finally null
>
> I wouldn't do it in production code though - IE will fail.
>
> On Jun 8, 8:29 pm, Raincole Lai <[email protected]> wrote:
> > I read an article<
> http://stackoverflow.com/questions/6276581/prototype-chain-cant-get-o..
> .>which
> > explains what prototype chain is.
> >
> > It says that if I try to access an object's property but it doesn't have
> it,
> > javascript engine will try it's .constructor.propotype. If it doesn't
> have
> > it either then try .construtor.propotype.constructor.propotype. Untill it
> > find the built-in Object().
> >
> > But I test this:
> >
> > function a() {}
> > b = new a();
> > c = b.constructor.prototype
> >
> > I get an empty a object.
> >
> > d = c.constructor.prototype
> >
> > I get an empty a object.
> >
> > It loops. No matter how many .constructor.prototype I call, it can't find
> > Object(). What's wrong? Do I misunderstand the prototype chain?
> >
> > --
> > Lai, Yu-Hsuan
>
> --
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--
Lai, Yu-Hsuan
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