The Java Tutorials have been written for JDK 8. Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.
See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.
Question 1: Consider the following two classes:
public class ClassA { public void methodOne(int i) { } public void methodTwo(int i) { } public static void methodThree(int i) { } public static void methodFour(int i) { } } public class ClassB extends ClassA { public static void methodOne(int i) { } public void methodTwo(int i) { } public void methodThree(int i) { } public static void methodFour(int i) { } }
Question 1a: Which method overrides a method in the superclass?
Answer 1a: methodTwo
Question 1b: Which method hides a method in the superclass?
Answer 1b: methodFour
Question 1c: What do the other methods do?
Answer 1c: They cause compile-time errors.
Question 2: Consider the
Card
,
Deck
, and
DisplayDeck
classes you wrote in the previous exercise. What Object
methods should each of these classes override?
Answer 2: Card
and Deck
should override equals
, hashCode
, and toString
.
Exercise 1: Write the implementations for the methods that you answered in question 2.
Answer 1: See
Card2
.