User Guide

Object 555
If you use the instanceof operator, you can also determine if an object belongs to a specified
class:
var my_str:String = new String("sven");
trace(my_str instanceof String); //output: true
However, in the following example the Object.constructor property converts primitive
data types (such as the string literal seen here) into wrapper objects. The
instanceof operator
does not perform any conversion, as seen in the following example:
var my_str:String = "sven";
trace(my_str.constructor == String); //output: true
trace(my_str instanceof String); //output: false
See also
instanceof operator
hasOwnProperty (Object.hasOwnProperty method)
public hasOwnProperty(name:String) : Boolean
Indicates whether an object has a specified property defined. This method returns true if the
target object has a property that matches the string specified by the
name parameter, and
false otherwise. This method does not check the object's prototype chain and returns true
only if the property exists on the object itself.
Availability: ActionScript 1.0; Flash Lite 2.0
Parameters
name:String -
Returns
Boolean - A Boolean value: true if the target object has the property specified by the name
parameter,
false otherwise.
isPropertyEnumerable
(Object.isPropertyEnumerable method)
public isPropertyEnumerable(name:String) : Boolean
Indicates whether the specified property exists and is enumerable. If true, then the property
exists and can be enumerated in a for..in loop. The property must exist on the target object
because this method does not check the target object's prototype chain.