OB Instance of

OB Instance of ( object ; class ) : Boolean

Parameter	Type		Description
object	Object	→	Object whose class is to be tested
class	Object	→	Class to test belongship
Function result	Boolean	←	True if object belongs to the specified class or a child class, and false otherwise

Description

The OB Instance of command returns true if object belongs to class or to one of its child classes, and false otherwise.

If class is not a valid Class object, the error -10745 is returned.

Example

You created the Polygon class:

  //Class: Polygon
 Class constructor
 var $1;$2 : Integer
 This.area:=$1*$2

Then, in a method, you can write:

 var $poly : Object
 var $instance : Boolean
 
 $poly:=cs.Polygon.new(4;3)
 
 $instance:=OB Instance of($poly;cs.Polygon)
  // true
 
 $instance:=OB Instance of($poly;4D.Object)
  // true 
 
 $instance:=OB Instance of($poly;cs.Circle)
  // false

See also

OB Class

Properties

Command number	1731
Thread safe	✓