Release 10.1A: OpenEdge Getting Started:
Object-oriented Programming

Using built-in system and object references

The Progress 4GL provides built-in system and object references to access instantiated class-based objects at run time. A built-in system reference (such as the THIS-OBJECT or SUPER system reference) returns a value set by Progress that represents a given class or class-based object depending on the class context where the reference occurs in a Progress session. A built-in object reference (such as the FIRST-OBJECT attribute on the SESSION system handle) is a value set by Progress that returns a user-defined class-based object that has been instantiated within the Progress session.

The values of different built-in system and object references are specified by unique keywords in the 4GL. The following sections describe these references.