Interesting, I've never seen that one, Alex... nicely expressive.
So, in summary, one can test the existent of a property with:
if (myObject.hasOwnProperty("property")) ...
if (myObject.property) ...
if (myObject["property"]) ...
if ("property" in myObject) ...
The first one is a function returning a Boolean. Obvious.
The second and third ones return the actual values, which implicitly convert
to true (for everything but null and "", which implicitly convert to false),
or if the property doesn't exist returns undefined, which implicitly
converts to false.
The fourth one... well, that's basically identical to the first one where it
returns a Boolean.
Troy.
On 5/24/07, Alex Harui <[EMAIL PROTECTED]> wrote:
if ("blah" in Object)
Should also work
-----Original Message-----
From: [email protected] <flexcoders%40yahoogroups.com> [mailto:
[email protected] <flexcoders%40yahoogroups.com>] On
Behalf Of Tom Chiverton
Sent: Thursday, May 24, 2007 6:53 AM
To: [email protected] <flexcoders%40yahoogroups.com>
Subject: Re: [flexcoders] Checking if an Object has as property/element
On Thursday 24 May 2007, Christopher Olsen wrote:
> If i do if Object.blah == null i get an error because blah doesn't
exist
hasOwnProperty(), or just if (Object.blah)
--
Tom Chiverton
Helping to globally maintain error-free solutions
on: http://thefalken.livejournal.com
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