Fragile Base Class
The fragile base class problem is a fundamental architectural problem of object-oriented programming systems where base classes (superclasses) are considered "fragile" because seemingly safe modifications to a base class, when inherited by the derived classes, may cause the derived classes to malfunction. The programmer cannot determine whether a base class change is safe simply by examining in isolation the methods of the base class.
One possible solution is to make instance variables private to their defining class and force subclasses to use accessors to modify superclass states. A language could also make it so that subclasses can control which inherited methods are exposed publicly. These changes prevent subclasses from relying on implementation details of superclasses and allow subclasses to expose only those superclass methods that are applicable to themselves.
Another alternative solution could be to have an interface instead of superclass.
Read more about Fragile Base Class: Solutions
Famous quotes containing the words fragile, base and/or class:
“Parents need all the help they can get. The strongest as well as the most fragile family requires a vital network of social supports.”
—Bernice Weissbourd (20th century)
“The worst of my actions or conditions seem not so ugly unto me as I find it both ugly and base not to dare to avouch for them.”
—Michel de Montaigne (1533–1592)
“We are the only class in history that has been left to fight its battles alone, unaided by the ruling powers. White labor and the freed black men had their champions, but where are ours?”
—Elizabeth Cady Stanton (1815–1902)