What is the purpose of the Enum class that was introduced in Java 5?

Question

My suggestions:

1) either enumexist only before compilation (for example, generics, but I never heard anything about it while he wrote everywhere that generic files are erased after compilation)

2), or Enum is a way to maintain backward compatibility in some way (but I don't see it yet).

Any other suggestions? (by the way, have you ever used it in your code?)

UPD: http://download.oracle.com/javase/1.5.0/docs/api/java/lang/Enum.html

In other words, there is a keyword enumand enum. They both appeared in Java 5. Question: why should we both?

Second question: why enumbecame part of the API?

Answer 1

From Java Tutorials :

You should use enumeration types anytime you need to represent a fixed set of constants. This includes natural types of enumerations, such as planets in our solar system and data sets where you know all the possible values ​​at compile time, such as menu selections, command line flags, etc.

Enumerations are extremely useful, and yes, I have used them many times in my code.

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Edit:

... there is an enum keyword and an Enum class. They both appeared in Java 5. Question: why do we need both?

This question is similar to the query "there is a keyword classand a class Object. Why do we need both?"

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Answer 2

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public final static int SALE=1, RETURN=2;
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public final static int SALE=1, RETURN=2;
public final static int DOMESTIC=1, FOREIGN=2;
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enum SaleType {SALE, RETURN};
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Answer 4

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Answer 5

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Answer 6

http://www.myhomepageindia.com/index.php/2009/07/08/enums-in-java-5-code-examples.html

Answer 7

. Javadoc

Answer 8

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public static final int OPTION_ONE = 1;
public static final int OPTION_TWO = 2;

public enum Option{one, two}

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                return client.checkinsNear(location.getLatitude(), location.getLongitude()).getList();
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        abstract List<Checkin> refreshList(Client client, Location location) throws IOException;
    }