The object reference for the previous ABL or .NET class instance in the list of instances created in the current ABL session. The value of this property is available after obtaining a valid object reference (for example, by using the SESSION:LAST-OBJECT attribute to obtain the object reference for the last class instance in the list). If there are no class object instances in the current session, or you have gone past the first class instance in the list, this attribute returns the Unknown value (?).
Data type: Progress.Lang.Object class
Access: PUBLIC Read-only
Applies to: Progress.Lang.Object class
Once your position in the list is established, you can use the NEXT-SIBLING and PREV-SIBLING properties to walk the list of class object instances.
There are two points worth noting about this property with garbage collection enabled:
To check the validity of an object reference, use the VALID-OBJECT function.