Question about C++ Classes

[Scott]

I am wondering what the point of using public, private, and protected variables and/or functions in a class. I understand how they work and everything, just not the reasoning.

I mean, is there any special benefit in having a variable set as private then having a public function which you call to retrieve them, instead of just setting everything to public and accessing it directly? (this is just based on tutorials and code examples I have seen)
_________________
Tutorial Management Script - Version 1.4 Released
TutorialToday - Up and running, submit your tutorials!
Linux Tutorials - Coming Soon

[mcwkm]

having a variable set to private makes the user not able to change the variable, adding a public function to retrieve the variable just gives them its value but does not let them change the variable

[krt]

mcwkm, I think he knows that but wants to know what the point is.

Scott, effectively, you could argue there is no point, in the same way you could argue against interfaces and abstract classes. The benefits are mostly in enforcement and can be useful for teams where there may be ambiguity as to what shouldn't be accessed from outside and what should. Basically, their purpose is to keep things organised promoting extensibility and maintainability.

Of course, the tutorials you see with those crude getter/setter methods for private variables give the wrong idea and I have no idea why tutorials use them the way they do, especially in abundance. The idea is to keep data in the class and return information (note the difference between data and information).

If you are interested in OOP, I strongly recommend a good book (as opposed to other aspects of development where tutorials can suffice at times). "Code Complete", "Thinking in Java" and "Design Patterns : Elements of Reusable Object-Oriented Software" are ones that come into mind. The first one is especially useful in getting across the concepts of OOP. The second one has a free ebook version and despite its name, it is not all specific to Java, the OOP related sections apply in general to languages.

[Pie32]

[Scott]

[exsanguination]