How can I find the type of a var/name in Actionscript3?

Question

Erm, that's it!...

Answer 1

flash.utils.getQualifiedClassName(...)

You can pass any ActionScript value to this function to get a String containing its fully qualified class name.

Answer 2

The function is called typeof(). http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/operators.html#typeof

Answer 3

If you only need the most fundamental description of it's type, then you can use the typeof operator, like so:

var foo:String = "test";
trace( typeof foo );
// string

While this is convenient it has a drawback. That being it always gives the base type of the variable, for example:

var foo:Array = ["A","B","C","D"];
trace( typeof foo );
//object

var bar:int = 5;
trace( typeof bar );
//number

var hummer:Car = new Car();
trace( typeof hummer );
//Vehicle

Which are both technically right, but may not be what you're looking for.

If you want the more specific type (ie Array, String etc.) then you need to use the slightly more complicated getQualifiedClassName() function from the flash.utils package:

import flash.utils.getQualifiedClassName;

var foo:Array = ["A","B","C","D"];
trace( getQualifiedClassName( foo ) );
//Array

var bar:int = 5;
trace( getQualifiedClassName( bar ) );
//int

var hummer:Car = new Car();
trace( getQualifiedClassName( hummer ) );
//Car

typeof documentation

getQualifiedClassName() documentation

Answer 4

If memory serves me right, a method flash.utils.describeType hands you an xml document with all reflected typeinfo of an object/type.

Indeed: http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/utils/package.html#describeType%28%29

Answer 5

The is operator is the up to date solution:

var mySprite:Sprite = new Sprite();
trace(mySprite is Sprite);           // true

See http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/operators.html?filter_flash=cs5&filter_flashplayer=10.2&filter_air=2.6#is