You can continue to use REXX's procedural instructions and intermix the use of objects as you become more comfortable with the technology. In object-oriented technology, programs use objects to model the real world. Similar objects are grouped into classes, and the classes themselves are arranged in hierarchies. A billing application, for example, can have an invoice class and a receipt class. These two classes might be members of a forms class.
Individual invoices are objects that are instances of the invoice class.
Each object contains all the data associated with it. To get at the data, you write instructions that send messages to the objects. These messages activate segments of code known as methods. As an object-oriented programmer, you solve problems by identifying and classifying objects related to the problem. Then, you determine what methods you need for those objects.