Procedual and OO programming ???

Question

i have just started learning java, i haven't done any programming before and i was wondering if someone could descride the diffrence between Procedual and OO programming, and maybe if its possibable give me a simple program in OO and the same program in Procedual?
so i can compare
thanks
Ant

Answer 1

Well, in procedural programming its kind of like writing a big list of things to do, all in a row, one thing after another ...like do this, then this, now go check this, then if that is done, go do this ...until you achieve the desired result. Once you are done, all those 'procedures' you wrote are locked into the program you just built, and the next time you start over making your program from scratch all over again (ok, you can copy paste ...but that's not very efficient) To track data for a set of people you have to maintain reams of data in more or less global variables, and pass this data around when you want to work on this group of people.
Now with oop, you will more or less write the same kind of syntax ...but you will use oop techniques and abilities to organize your code so that it becomes reusable by other programs. Its kind of akin to organizing your code a certain way. In the procedural style ...you can write the same functionality a million different ways, with stuff all disjointed and scattered throughout your program. However, with oop techniques, you try to make an intelligent object that can 'do its job in and of itself' ...almost independent of the program you wrote it for.
For example, with class Person, we would write a class that stores info about eye color, hair style, sex, etc, etc. We give the class its own methods such as getThoughts(), isSleeping() etc, etc. Because this is an object, we can make person after person after person ...and we don't have to track anything about the different paople. The class handles all this internally, and we can forget about it. The data is encapsulated inside the class and protected from access (unless we specifically go retreive it) from the outside program. When we want to get the thoughts for a person we have created, we just call getThoughts() and count on the code inside of each different person object to act on its data, compute the results for us, and give it back.
The best part is when you write another program, you just reuse the person class again. No rewriting of code. If you want to add a bit of customization to your people for this program ...you can inherit (or extend) the original person class to take advantage of its basic features, and add your customized functionality in your subclass. This saves time, and saves debugging too. If the person class is tested and debugged ...we avoid screwing it up by not rewriting the same code all over again. We just use the prebuilt person object we made last year.
Hope this sheds a few lights. Others ...please feel free to add or complain. Its not something you explain conceptually in a couple of words or even paragraghs !!
GumB.