From: "Edward Diener"
David Abrahams wrote:
"Edward Diener" <eddielee@tropicsoft.com> writes:
If you are making designs that would normally have a lot of getters and setters, it suggests that they may have an insufficient level of abstraction. Of course, that isn't neccessarily the case -- but it does seem to be the rule in my code. I personally don't have a need for this facility and I don't think I want a library that would encourage that style.
I don't see what getters and setters have to do with levels of abstraction. Needless to say I see nothing wrong with the style that uses properties, but since you didn't say what bothers you about that style I can't answer for why you don't like it. Care to explain ?
When classes have a lot of getters and setters or, equivalently, exposed properties that are just reflections of underlying data members, they usually represent just a collection of exposed data values rather than a higher level of abstraction.
Properties do not have to be data members at all but just values may be set anywhere, ie. a file on disk or a database, and a number of properties may refer to a single underlying object within the actual object having the property.
It doesn't matter. Properties represent degrees of freedom. They don't describe dependent data well. As a relatively simple example, consider a pair of integers (x, y) that has an invariant of x*x + y*y = 25, and try to move from (3, 4) to (4, 3) by using the X and Y properties.