CSE 8B Lecture 9: Interface and Recursion
11 Feb 2017
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Cannot be instantiated as an object: too general/ generic to be defined as an object. Used as a superclass for inheritance and polymorphism. Can define some of its methods, but its abstract methods are the ones that the subclasses must implement. Used in place of abstract class when there is no default implementation to inherit. Can only declare public abstract method declarations & public static final constants. More flexible than classes: can define common super type for unrelated classes. No data/ method implementation is inherited subclass must implement all of the methods defined in the interface. If a class implements an interface, then that class"s type is also that interface type. Cannot create an instance, but you can create a reference variable of the interface type. Recursion is when a method calls itself within its method body. Why do we use it: perfect for problems where there is an obvious answer for some small problem.
