CS180 Week 12: Polymorphism and Abstraction

Abstract class

cannot be instantiated, some methods may be unimplemented, may include some implemented methods with defualt methods

dynamic binding

methods selected at runtime based on the class of the objects referenced, not the class of the variable that holds the object reference

why polymorphism?

generic treatment of objects, ex) array of animals, programmer must be disciplined to ensure overridden methods consistently implement expected behavior.

what fields does a subclass contatin

its own and superclass

if you have even one abstract method, the whole class needs to be

abstract also

true or false abstract classes can have instance vriables

true -> name vs dog name

abstract methods

may be declared abstract, provide only header no body, class must then also be declared abstract