The three special types are the untyped specifier (*),
void
, and Null
.
Type | Description | |
---|---|---|
* | Specifies that a property is untyped. | |
void | Specifies that a function cannot return any value. | |
Null | A special data type that represents the lack of a value. |
* | Special Type |
 
propertyName:*
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9 |
Specifies that a property is untyped. Use of the asterisk symbol for a type annotation is equivalent to using no type annotation. Expressions that read from untyped properties are considered untyped expressions. Use of untyped expressions or properties is recommended in the following circumstances:
- When you want to defer type checking to runtime. You can use an untyped property or expression to circumvent compile-time type checking in strict mode. Note, however, that runtime type checking of assignment statements occurs whether you use strict mode or not.
- When you want to store the value
undefined
in a property. Unlike previous versions of ActionScript, the valueundefined
is not a member of the Object data type. You must use an untyped property to store the valueundefined
.
See also
void | Special Type |
 
functionName():void {}
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9 |
Specifies that a function cannot return any value. The void
type is a special type that contains exactly one value: undefined
.
It is special in that its use is limited to the return type of a function. You cannot use void
as a type annotation for a property.
See also
Null | Special Type |
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9 |
A special data type that represents the lack of a value. The Null
data type includes only one value: null
. The Null
data type is special in that it is not associated with a class. This means that you cannot use the Null
data type as a type annotation for a property.
See also
Fri Mar 19 2010, 03:06 AM -07:00