An object of subclass can be treated as an object of the super class. Abstract methods have no implementations because the abstract classes are.
Though a final class cannot be extended it can extend other classes. In simpler It can have abstract and non-abstract methods (method with body).
We can make Person an abstract class: Person objects cannot be created but subclass Error function must be implemented in each derived. // class and a ...
We now have two classes that do essentially the Objects can share functionality by extending another ... The subclass can add new fields/methods.
class Tea extends Beverage {. } We get the following error: >javac Tea.java. Tea.java:3: Can't subclass final classes: class cert.Beverage class Tea extends
10 Apr 2008 To introduce the notions of abstract methods abstract classes
25 Apr 2022 Java lets you write method code in an interface that you might not ... Note that a sealed class must have at least one subclass.
https://cmu-17-214.github.io/f2021/slides/20210928-Inheritance-and-delegation.pdf
public final class FilledRectangle extends Rectangle { public int red green
extends. 3. A subclass can have only one superclass because Java doesn't support multiple implementation inheritance. 4. You prevent a class from being