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

Advantages of classes in the 4GL

This 4GL support for object-oriented programming provides the following benefits for Progress application development:

Classes support a powerful programming model by encapsulating related functionality into objects. The benefit of organized code is especially important for maintenance, where changes or enhancements can be limited to the objects that are affected by the change.
Classes enhance code reuse. Common code can be put into one class and shared among other related classes. The related classes can provide specialized behavior whenever necessary to extend the initial class functionality, as well as the functionality of other related classes.
Classes provide strong typing that enables Progress to do compile-time checking in order to catch errors before the code is deployed or executed. This compile-time checking verifies all interfaces for correctness, not just the ones that are accessed during testing.
The object-oriented support using classes maps much more closely to the constructs used in a service-oriented architecture (SOA) and to those used by modeling tools and other design tools that are increasingly used to provide a basis for application design, and even code generation.