Duplicate property names (was Re: @@new)

Andy Wingo wingo at igalia.com
Fri Jun 20 01:48:27 PDT 2014

On Thu 19 Jun 2014 18:02, "Mark S. Miller" <erights at google.com> writes:

> Yes. For both strict and sloppy, for both static/literal and
> dynamic/computed, duplicate property names/symbols in object literals
> are no longer an error. Instead, in left-to-right order, each cause the
> equivalent of a [[DefineOwnProperty]] on the new object, so that
> rightward definitions silently overwrite conflicting leftward
> definitions. This should not result in any change to sloppy literals. It
> just makes strict literals, regarding this issue alone, act like sloppy
> literals. (Once we have a way to express that a property is to be
> initialized to a non-configurable state, we'll need to revisit this. But
> that's after ES6.)

There is one change:

  ({ foo: 3, get foo() { return 4 } })

This is not allowed with current sloppy mode.  Are you proposing that it
be allowed, given that this situation may arise with computed property

  ({ ['foo']: 3, get foo() { return 4 } })


  ({ foo: 3, get ['foo']() { return 4 } })


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