The examples in the following sections compare the use of classes and inheritance with the use of procedures and super procedures. Almost the same application is implemented using a set of sample classes and procedures, which checks, adjusts, and reports on customer credit limits. A summary comparison between the class-based and procedure-based versions follows the listing of all the classes and procedures. The commented numbers in the code match code-numbered comments in the summary comparison.
Note that this is not a real-world application. It is designed solely to demonstrate object-oriented programming concepts, and it includes one possible implementation using procedure-based programming as a point of comparison with the class-based implementation. As a result, some constructs are artificially coded for point-by-point illustration and comparison. Little of this code is intended to demonstrate best practices for designing and implementing ABL applications. Indeed for brevity, some best practices might be intentionally avoided to illustrate a concept. For information on best practices, see the resources available on PSDN:
http://communities.progress.com/pcom/community/psdn/openedge.
These sample classes and procedures are also available for compiling and running in your OpenEdge development environment.
