Thread: Protected attributes in a class hierarchy

Hello,

Here I am immersed in the language of C + + Stroustrup and noted that using the keyword protected for attributes in a class hierarchy is banned because taken out of the data corruption. The standard therefore it is to declare all attributes private and set accessors protected if used in subclasses is necessary? If yes why?

Thank you

Yes (this is true whatever the language) is the ideal, but it is not enough. We need the accessors do their job i.e. checks the validity of data.

The goal is to make the wrong change attributes impossible to make the code robust.

You can give a more precise reference because as you quote, I want to say I do not agree. But I may close on the context that would help a better understanding.

You still have to show how it makes the code more robust rather than say it does. Between accessors and make more accessible the member, I can not see the difference. I do neither one nor the other; I prefer to provide interfaces with meaning, and therefore doing more than recovering and especially as editing member isolation.

1. For completeness, I would add:

The C + + offers a range of tools. Nothing forbids you to take a screwdriver to hammer a nail ... but good.

We must distinguish several types of inheritance, especially their right. If you've superclass and only willing to provide these attributes in subclass (eg with a manufacturer protected), nothing forbids you to put in some protected -> your class will have a target, provide attributes!

After it is often of Design Pattern. They each have their good and bad side (and contrary to what some would have us believe, there is no ultimate DP what we can not escape!).