Le 09/11/2011 02:26, Andrew Paprocki a écrit :
On Tue, Nov 8, 2011 at 6:36 PM, Brendan Eich<bren...@mozilla.com> wrote:
Ignoring performance, a lot of stylish JS hackers use Object.keys(o).forEach.
How many run into the wrong |this| (arguments/break/continue/return)? Not
clear. Something to study.
I was curious so I did some grok-ing across my code sample and
Object.keys() is barely used. The usage of the |for in| construct is 2
orders of magnitude larger than the usage of hasOwnProperty(),
supporting the thought that no one really does it the "right" way.
The MDN page for Object.keys does not talk about |this| being wrong in
certain situations. If you could elaborate on that, it would be
helpful to know.
The |this| differs between the body of a for-in and the argument
callback in the .forEach. Nothing to do with Object.keys. .forEach has a
second optional argument which is the value to be used as |this| so that
you don't have to do a .bind.
David
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