Comments on: Q&A – is, as, and type conversion

By: adehaas

adehaas — Sun, 01 Feb 2009 12:10:00 +0000

Thanks for that, nice refresher on this topic!

By: Mims H Wright

Mims H Wright — Tue, 27 Jan 2009 19:04:51 +0000

Dan & Grant, Good points. I should have mentioned that. Using the type cast can actually convert an object into the other class even if they are not the same type. In fact, Array(obj) should always be replaced with ‘as’ because it’s the equivalent of using new Array(obj).
I would also recommend always using as for type casting.

By: Grant Skinner

Grant Skinner — Tue, 27 Jan 2009 16:34:44 +0000

It’s also worth noting that the syntax for type casting is an overloaded syntax, which makes it ambiguous. In some cases it casts the type, in others it attempts a type conversion.

TextField(myvar) // casts
String(myvar) // converts

I use “as” for all casting, and only use the above syntax for conversion. This keeps the intent clear.

By: Dan

Dan — Tue, 27 Jan 2009 15:06:24 +0000

Hey, should add that Type(object) in some cases actually converts the object, like with XML/XMLList.. one of the slightly arcane aspects of AS3.

Cheers, Dan