in fairness, I just skimmed over it and need to read it again
a program that you can safely ignore while working on any one section of code. Classes are the primary tool for accomplishing that objective.
Treat yourself to the highest possible level of abstraction.
That argument fails the main test for inheritance, which is, "Is inheritance used only for "is a" relationships?" To inherit from ListContainer would mean that EmployeeCensus "is a" ListContainer, which obviously isn't true. If the abstraction of the EmployeeCensus object is that it can be searched or sorted, that should be incorporated as an explicit, consistent part of the class interface.
related—a class interface that presents a good abstraction usually has strong cohesion. Classes with strong cohesion tend to present good abstractions, although that relationship is not as strong.
Minimize accessibility of classes and members. Avoid friend classes, because they're tightly coupled. Make data private rather than protected in a base class to make derived classes less tightly coupled to the base class. Avoid exposing member data in a class's public interface. Be wary of semantic violations of encapsulation. Observe the "Law of Demeter" (discussed in Design and Implementation Issues of this chapter).
Containment is the simple idea that a class contains a primitive data element or object.
If inheritance is a chain saw, multiple inheritance is a 1950s-era chain saw with no blade guard, no automatic shutoff, and a finicky engine.
inheritance tends to work against the primary technical imperative you have as a programmer, which is to manage complexity.
Page created on 6 Jun 2020