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.
Answer: False. All enums implicitly extend java.lang.Enum. Because a class can only extend one parent, the Java language does not support multiple inheritance of state, and therefore an enum cannot extend anything else.
Exercise: Rewrite the class Card
from the exercise in
Questions and Exercises: Classes so that it represents the rank and suit of a card with enum types.
Answer: See
Card3.java
,
Suit.java
, and
Rank.java
.
Exercise: Rewrite the Deck
class.
Answer: See
Deck3.java
.