Comments on: as3 casting issue

By: Jason Langdon

Jason Langdon — Sat, 17 Jan 2009 00:26:06 +0000

Errrr, actually true is equal to “true”. But it ain’t equal to “” ;-)

By: Josh Tynjala

Josh Tynjala — Fri, 16 Jan 2009 20:20:20 +0000

true != “true”

By: Jason Langdon

Jason Langdon — Fri, 16 Jan 2009 12:03:28 +0000

Ahhh, true dat Nat ;-)

I would normally use just the [] array literal, but was declaring this particular array amongst a bunch of others that were all using (apparently not optimally) new Array(…)

I read the conventions link you posted and I quote, “Use the Array constructor only to allocate an array of a prespecified size, as in new Array(3), which means [ undefined, undefined, undefined ], not [ 3 ].” So out with new Array() (which to be fair is a bit more descriptive) and in with [] from hence forth.

By: Nat

Nat — Fri, 16 Jan 2009 10:17:31 +0000

Why not just use the Use Array literals [] directly:

var myArray:Array = [ 1 ];

btw it’s actually recommended by Adobe also:
http://opensource.adobe.com/wiki/display/flexsdk/Coding Conventions

Do this:
[]
Not this:
new Array()

And this:
[ 1, 2, 3 ]
Not this:
new Array(1, 2, 3)

By: Jason Langdon

Jason Langdon — Thu, 15 Jan 2009 21:45:33 +0000

Possibly as a reminder to myself rather than an attempt to illuminate those of you out there who have a solid grasp of as3 - defining a new Array with one numeric argument in the constructor will create an array with the specified number of empty placeholder elements. Yup, took me another 5 minutes there to figure out that Array’s are behaving as they’re meant to, I’m just having an off syntactical day! So if you want to add the number 1 to an new array do so like this

new Array([1]);

And please don’t ask why I even have to do this…

By: Jason Langdon

Jason Langdon — Thu, 15 Jan 2009 18:59:52 +0000

@senocular - thanks for the clarification on that. I am definitely after the conversion in this instance, and didn’t realise that the “as” operator wasn’t doing that for me.

@Theo - hey, nice to see you on my little patch of turf and not in the Mate/asfusion forums ;-)

By: senocular

senocular — Thu, 15 Jan 2009 18:55:31 +0000

Constructor casting in some cases also involves a conversion function. For example, with String, String() is actually a conversion function - it’s doing more than casting. It will take a value and make it a string (usually by invoking the object’s toString() method).

By: Theo

Theo — Thu, 15 Jan 2009 18:50:10 +0000

Yeah, the “as” operator yields null if the cast fails, the regular cast yields an error. It’s in the docs.