[snip] >The other day I had a Java programmer explain to me that >the OO difference is not necessarily how you develop one >program using a bunch of different classes and objects >but rather how they are stored in memory when they are >called. OO is all about modeling your software to look like your real-world environment. It takes it a step farther by introducing abstraction, inheritance, encapsulation and polymorphism. All of these concepts when used properly make your system more scalable, maintainable, adaptable and reusable. I would say that your Java programmer has master the language syntax, but not the concepts of OO. >Only one copy of a program is stored in memory in Java >and all programs making a call to that particular program >are always referencing that same one. The class is loaded into the JVM the first time it is referenced. Then you would make instances of it. Think of a blueprint to make buildings. The class is a blueprint and each building you make is an object. You can't open the door on a blueprint and walk in. You first must make a building based on the blueprint. That is what classes and objects are. It is also possible to use threads for multiple flows of execution within a single object. That is how servlets work. Think of executing a subroutine or calling a procedure in your RPG program, except that your mainline continues to execute at the same time that your subroutine/procedure is executing. >Is this also true for RPGILE type programming? [snip] You can simulate many of these things in RPG/ILE now, but requires considerable effort and knowledge of the system. With Java, the language was built on these concepts, so they are quite simple to implement. It does require that you learn the OO concepts to do it well. Joe Teff +--- | This is the JAVA/400 Mailing List! | To submit a new message, send your mail to JAVA400-L@midrange.com. | To subscribe to this list send email to JAVA400-L-SUB@midrange.com. | To unsubscribe from this list send email to JAVA400-L-UNSUB@midrange.com. | Questions should be directed to the list owner: email@example.com +---
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