Are internal data properties ever inherited?

Brendan Eich brendan at
Mon Oct 7 21:19:58 PDT 2013

> Nathan Wall <mailto:nathan.wall at>
> October 7, 2013 8:05 PM
> This should be a quick answer; I'm just looking for clarity.  Are 
> there any situations where internal data properties may be inherited? 
>  For example:
>     Set foo to bar.[[Baz]]
> Does `foo` ever result in a non-undefined value if `bar` doesn't have 
> an own `[[Baz]]` property but inherits from an object that has an 
> internal `[[Baz]]` property?

How would you name the internal property?

If there's a symbol name, then use that, and yes: inherited just as for 
string-equated property names.

If truly internal, then there's no way to write what you wrote above 
with double-square-brackets.


More information about the es-discuss mailing list